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INCH-POUND
MIL-DTL-83731C
30 March 2004
SUPERSEDING
MIL-DTL-83731B
21 April 1999

DETAIL SPECIFICATION

SWITCHES, TOGGLE, UNSEALED AND SEALED,

GENERAL SPECIFICATION FOR

This specification is approved for use by all Depart-

ments and Agencies of the Department of Defense.

1. SCOPE

1.1 Scope. This specification covers the military requirements for unsealed and toggle sealed toggle
switches.

2. APPLICABLE DOCUMENTS

2.1 General. The documents listed in this section are specified in sections 3 and 4 of this specification.
This section does not include documents cited in other sections of this specification or recommended for
additional information or as examples. While every effort has been made to ensure completeness of this list,
document users are cautioned that they must meet all specified requirement documents cited in section 3 and 4
of this specification, whether or not they are listed.

2.2 Government documents.

2.2.1 Specifications, standards and handbooks. The following specifications and standards form a part of
this document to the extent specified herein. Unless otherwise specified, the issues of these documents are
those listed in the issue of the Department of Defense Index of Specifications and Standards (DODISS) and
supplement thereto, cited in the solicitation (see 6.2).

SPECIFICATIONS

DEPARTMENT OF DEFENSE

MIL-W-5086 Wire, Electrical, Hook-up and Interconnecting, Polyvinyl Chloride Insulation,

Nylon Jacket, Tin-Coated Copper Conductor, 600 Volt, 105°C.
MIL-DTL-5624 Turbine Fuel Aviation, Grade JP-4 or JP-5.
MIL-PRF-7808 Lubricating Oil, Aircraft Turbine Engine, Synthetic Base.
MIL-PRF-15160/2 Fuses, Instrument, Power and Telephone.
MIL-PRF-87252 Coolant Fluid, Hydrolytically Stable, Dielectric

FEDERAL
FED-STD-H28 Screw Thread Standards for Federal Services.

Comments, suggestions or questions on this document should be addressed to Defense Supply Center
Columbus, ATTN: VAT, Post Office Box 3990, Columbus, OH 43216-5000, or emailed to switch@dla.mil.
Since contact information can change, you may want to verify the currency of this address information using
the ASSIST Online database at www.dodssp.daps.mil.

AMSC N/A FSC 5930

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MIL-DTL-83731C

DEPARTMENT OF DEFENSE
MIL-STD-202 Test Methods for Electronic and Electrical Component Parts
MIL-STD-1285 Marking of Electrical and Electronic Parts.

(Copies of these documents are available online at http://assist.daps.dla.mil/quicksearch/ or

www.dodssp.daps.mil or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D,
Philadelphia, PA 19111-5094.)

2.3 Non-Government publications. The following documents form a part of this document to the extent
specified herein. Unless otherwise specified, the issue of the documents which are DoD adopted are those
listed in the issue of the DODISS cited in the solicitation. Unless otherwise specified, the issues of documents
not listed in the DODISS are the issues of the documents cited in the solicitation (see 6.2).

AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI)

ANSI/J-STD-002 Solderability Tests for Component Leads, Termination’s, Lugs, Terminals and
Wires.
ANSI/NCSL Z540.1 General Requirements for Calibration Laboratories and Measuring and Test
Equipment.

(Copies of these documents are available online at http://dod.nssn.org/search.html or from the American
National Standards Institute (ANSI), 11 West 42nd Street, New York, NY 10036-8002, telephone 212-642-
4900, fax 212-302-1286.)

AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)

ASTM E 1119 Glycol, Industrial Grade Ethylene, Standard Specification for.

(Copies of these documents are available online at www.astm.org or from the American Society for Testing
and Materials, 100 Barr Harbor Drive, West Conshohocken, Pennsylvania, 19428-2959.)

INTERNATIONAL ORGANIZATION FOR STANDARDS (ISO)

ISO 10012-1 Quality assurance requirements for measuring equipment - Part 1;

Meteorological confirmation system for measuring equipment.

(Copies of these documents are available online at www.nssn.org/search.html or from the American National
Standards Institute (ANSI), 11 West 42nd Street, New York, NY 10036-8002, telephone 212-642-4900, fax
212-302-1286.)

SOCIETY OF AUTOMOTIVE ENGINEERS

SAE-AS7928 Terminals, Lug: Splices, Conductor: Crimp Style Copper, General

Specification for.

(Copies of these documents are available online at www.sae.org or from Society of Automotive Engineers,
400 Commonwealth Drive, Warrendale, Pennsylvania, 15096-0001)

UNDERWRITERS’ LABORATORIES, INC. (UL)

UL94 Tests for Flammability of Plastic Materials for Parts in Devices and Appliances.

(Copies of these documents are available online at www.ul.com or from the Underwriters Laboratories, Inc.,
333 Pfingsten Road, Northbrook, IL 60062-2002.)

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2.4 Order of precedence. In the event of a conflict between the text of this document and the references
cited herein (except for related associated detail specifications or specification sheets), the text of this document
takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless
specific exemption has been obtained.

3. REQUIREMENTS

3.1 MS military standards or military specification sheets. Individual switch requirements shall be as
specified herein and in accordance with the applicable MS military standard or military specification sheet. In the
event of any conflict between the requirements of this specification and the MS military standard or military
specification sheet, the latter shall govern.

3.2 Switch categories. Switches furnished under this specification shall be category I, or II, as defined in
3.2.1, or 3.2.2, respectively.

3.2.1 Category I switches. Switches completely defined by an MS military standard or military specification
sheet. Category I switches shall be ordered in accordance with 6.2.1.

3.2.2 Category II switches. Switches the same as category I switches except for minor differences such as
termination configuration, operating characteristics, and minor actuator variations, which do not change the basic
design or construction of the qualified item. Category II switches shall be procured from a source listed on the
applicable qualified products list for the particular similar product in category I. Category II switches shall be
ordered in accordance with 6.2.2. These switches are nonstandard.

3.3 Qualification. Category I switches furnished under this specification shall be products that are
manufactured by a manufacturer authorized by the qualifying activity for listing on the applicable qualified
products list before contract award. (see 4.4 and 6.3)

3.4 Materials. Materials shall be used which will enable the switches to meet the performance requirements
of this specification. Acceptance or approval of any constituent material shall not be construed as a guaranty of
acceptance of the finished product.

3.4.1 Metals. All metal parts, other than current carrying parts, shall be of corrosion resistant material or
shall be suitably protected to resist corrosion.

3.4.1.1 Ferrous material. Ferrous material shall not be used for current carrying parts.

3.4.1.2 Dissimilar metals. Dissimilar metals shall not be used in intimate contact with each other unless
suitably protected against electrolytic corrosion. Dissimilar metals are defined as metal specimens that are in
contact or otherwise electrically connected to each other in a conductive solution to generate an electrical
current. For additional information and guidance on dissimilar metals see 6.8.

3.4.2 Insulation. Materials for insulation shall be used which will enable the switch to meet the performance
requirements of this specification. Plastic materials shall be fungus inert and shall meet flammability
requirements of V-0 in accordance with UL94. For additional information and guidance on ceramic and
thermoplastic material see 6.9.

3.4.3 Silicone rubber. Silicone rubber parts, when used, shall be selected to enable the switch to meet the
performance requirements of this specification. For additional information and guidance on silicone rubber
material see 6.10.

3.4.4 Potting compounds. Potting compounds, when used, shall be selected to enable the switch to meet
the performance requirements of this specification. For additional information and guidance on potting
compounds, see 6.11.

3.5 Interface and dimensions. Switches shall be so constructed as to insure proper operation when mounted
in any position. The switches shall meet the interface and dimensions specified (see 3.1).

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3.5.1 Toggle lever. The toggle lever shall have a lusterless finish and shall be insulated from all current
carrying parts.

3.5.2 Terminals. Terminals shall be as specified (see 3.1). Only the number of terminals required to
accomplish the circuit characteristics shall be furnished.

3.5.2.1 Solderable terminals. Solderable terminals shall be treated to facilitate soldering. Silver plating shall
not be used as an external coating. Terminals shall be designed so that wires can be mechanically secured
prior to soldering. Terminals may be tapped or drilled after coating.

3.5.2.2 Screw terminals. Screw terminals shall be provided with the hardware specified (see 3.1 and the
appendix).

3.5.2.3 Integrated wire termination. Switches with integrated wire termination shall be designed to accept
terminal pins as specified (see 3.1).

3.5.3 Mounting bushing. The mounting bushing shall be as specified (see 3.1). For toggle sealed switches,
the bushing shall be provided with a seal between the toggle lever and the switching mechanism. The body of
the elastomer seal shall not protrude from the top of the bushing with the exception of the tapered joint or
meniscus where the seal joins the toggle lever, which may be permitted to exceed the height of the mounting
bushing slightly.

3.5.3.1 Anti-rotational means. All switches shall be designed to have an anti-rotational mounting means
which shall be as specified (see 3.1).

3.5.4 Hardware. Each switch shall be provided with the mounting and terminal hardware as specified (see
3.1and the appendix). Crimp pin contacts, for switches with integrated wire termination, are not supplied with
the switch.

3.5.5 Screw threads. Screw threads on external threaded parts shall be in accordance with FED-STD-H28.
All threaded parts shall engage by at least two full threads. Threading of nonmetallic parts is not permitted.

3.5.6 Weight. Weight shall be as specified (see 3.1).

3.6 Performance.

3.6.1 Solderability (applicable to solderable terminals). When tested as specified in 4.7.2, solder shall be
of such a quality as to enable the switch to meet the performance requirements of this specification. For
guidance on solder, see 6.12. Solder shall not be used to obtain mechanical strength.

3.6.2 Resistance to soldering heat (applicable to solderable terminals). When switches are tested as
specified in 4.7.3, the switches shall remain operable. When opened, there shall be no internal deformation or
damage.

3.6.3 Switching characteristics. When tested as specified in 4.7.4, switches shall operate as specified (See
3.1).

3.6.4 Strength of terminals. When switches are tested as specified in 4.7.5, there shall be no breakage,
loosening or rotating of terminals, and no damage to the switch.

3.6.5 Strength of toggle lever, pivot and lever stop. When switches are tested as specified in 4.7.6, there
shall be no malfunction, damage, breakage or short circuit; switches shall operate mechanically and electrically.

3.6.6 Strength of mounting bushing. When switches are tested as specified in 4.7.7, there shall be no
loosening of the mounting bushing or other mechanical damage.

3.6.7 Contact voltage drop. When switches are tested as specified in 4.7.8, the contact voltage drop shall
not exceed 2.5 millivolts initially and 5 millivolts after mechanical endurance.

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3.6.8 Dielectric withstanding voltage. When switches are tested as specified in 4.7.9, the switches shall
withstand the application of the specified voltages without arcing, flashover, breakdown of insulation, or damage;
there shall be no momentary flashover or leakage current in excess of 500 microamperes.

3.6.9 Mechanical endurance. When switches are tested as specified in 4.7.10, there shall be no
deterioration of the toggle seal, mechanical breakage or malfunction. Circuitry and degree of toggle lever
movement shall be as specified (see 3.1).

3.6.10 Electrical overload, electrical endurance, intermediate current and temperature rise. When switches
are tested as specified in 4.7.11, each pair of switch contacts under test shall open and close the circuit in
proper sequence during each cycle of the switch actuating member. There shall be no malfunction or damage
during or after the test and any blown fuse or tripped circuit breaker shall constitute failure. When switches are
tested as specified in 4.7.11.6, the temperature rise of the switch terminals shall not exceed 50°C. At the
conclusion of the test, switches shall be electrically and mechanically operable while controlling the test load, at
the test environment and at room conditions. Electrical tolerances are as follows:

Voltage: + 5 percent for 28 V, 125 V, and 250 V; DC

+ 7 percent for 125 V and 250 V; AC
Frequency: + 5 percent
Current: + 5 percent on all voltages

3.6.11 Short circuit. When tested as specified in 4.7.12, switch contacts under test shall open after each
closure and there shall be no mechanical failure or electrical damage.

3.6.12 Vibration. When switches are tested as specified in 4.7.13, there shall be no separation of closed
contacts or closure of open contacts in excess of 10 microseconds. There shall be no damage.

3.6.13 Shock. When switches are tested as specified in 4.7.14, there shall be no separation of closed
contacts or closure of open contacts in excess of 10 microseconds for Method I (see 4.7.14.1), and 20
milliseconds for Method II (see 4.7.14.2). There shall be no damage.

3.6.14 Salt spray (corrosion). When switches are tested as specified in 4.7.15, there shall be no warping,
cracking, excessive corrosion, or other damage and the specified cycling shall be completed without failure. The
mounting hardware shall be readily removable at the conclusion of the test.

3.6.15 Thermal shock. When switches are tested as specified in 4.7.16, there shall be no mechanical or
electrical damage, or loosening of rivets or other fastening devices.

3.6.16 Moisture resistance. When switches are tested as specified in 4.7.17, there shall be no electrical
failures, or breaking, spalling, cracking or loosening of terminals.

3.6.17 Sand and dust. When switches are tested as specified in 4.7.18, switches shall, at the conclusion of
the test, be electrically and mechanically operable as evidenced by ability to control a pilot lamp circuit.

3.6.18 Explosion. When switches are tested as specified in 4.7.19, there shall be no explosion within the test
chamber whether or not explosion occurs within the switch.

3.6.19 Toggle seal (applicable to toggle seal switches only). When switches are tested as specified in
4.7.20, there shall be no leakage of water into the switch due to entry through the toggle seal.

3.6.20 Terminal sealing, fluid submersion (applicable to switches with integrated wire terminals). When
switches are tested as specified in 4.7.21, the switches shall meet the requirements for dielectric withstanding
voltage, there shall be no cracking, loosening of bonds and seams, and the switches shall be operable.

3.7 Marking.

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3.7.1 Identification of product. As a minimum, switches shall be marked in accordance with MIL-STD-1285
as follows:
(a) MS military standard part number or M number (category I only).
(b) Manufacturer’s part number (category II only).
(c) Manufacturer’s name, trademark or source code.
(d) Date code
(e) Switch positions (on-off, etc.).

3.7.2 Terminal identification. When specified (see 3.1), terminals shall be marked in accordance with
figure 1. Terminal positions not used need not be identified. Terminal marking on the side of the case is
permissible.

1 1 4 1 4 7 10

2 2 5 2 5 8 11

3 3 6 3 6 9 12

SINGLE POLE DOUBLE POLE FOUR POLE

NOTES:
1. All views are rear of switch with keyway or flat down as applicable (see 3.1).
2. Terminals 2, 2 and 5, and 5 and 8 are considered inboard terminals for single, two and four pole,
respectively. All others are outboard terminals.

FIGURE 1. Terminal Identification.

3.8 Recycled, recovered, or environmentally preferable materials. Recycled, recovered, or environmentally

referable materials should be used to the maximum extent possible provided that the material meets or exceeds
the operational and maintenance requirements, and promotes economically advantageous life cycle costs.

3.9 Workmanship. Switches shall be processed in such a manner to be free from cracked or displaced
parts, sharp edges, burrs and other defects which will affect life, serviceability or appearance.

4. VERIFICATION

4.1 Classification of inspection. The inspections specified herein are classified as follows:

(a) Qualification Inspection (see 4.4).

(b) Inspection requirement for Category II (see 4.5).
(c) Conformance Inspection (see 4.6).

4.2 Test equipment and inspection facilities. Test and measuring equipment and inspection facilities of
sufficient accuracy, quality and quantity to permit performance of the required inspection shall be established
and maintained by the supplier. The establishment and maintenance of a calibration system to control accuracy
of the measuring and test equipment shall be in accordance with ANSI/NCSL Z540.1, ISO-10012-1 or equivalent
system as approved by the qualifying activity.

4.3 Inspection conditions. Unless otherwise specified herein, all inspections shall be performed in
accordance with the test conditions specified in the General Requirements of MIL-STD-202.

4.4 Qualification inspection. Qualification inspection shall be performed at a laboratory acceptable to the
Government (see 6.3), on sample units produced with equipment and procedures normally used in production.

4.4.1 Sample size. The number of switches to be subjected to qualification inspection shall be as specified
in table I.
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4.4.2 Inspection Routine.

4.4.2.1 Single submission. A sample consisting of the required number of specimens of each switch shall be
submitted. Qualification shall be restricted to the type submitted.

4.4.2.2 Group submission. A sample consisting of the required number of specimens of each basic switch
listed in table II shall be submitted and shall be subjected to the qualification test sequence in table I in the order
shown. In addition, two specimens of each of the other switches listed in table II shall be submitted and shall be
subjected to visual and mechanical examination and switching characteristics test of table I.

4.4.3 Failures. Failure of any switch to comply with the applicable requirements shall be cause for refusal
to grant qualification.

4.4.4 Verification of qualification. Every 12 months, the manufacturer shall provide verification of qualification
to the qualifying activity. Continuation is based on meeting the following requirements:

a. Design of the switch has not been modified (every 12 months).

b. Verification of group A lot acceptance (every 12 months) (see 4.6.2)

c. Periodic group B inspection (every 36 months) (see 4.6.3).

4.5 Inspection requirements for category II switches (see 3.2.2). Inspection requirements for category II shall
be performed by the contractor after award of contract and prior production. Additional tests to verify suitability
of the variations from the category I switches shall be performed as specified (see 6.2.2).

4.6 Conformance Inspection. Inspection of product for delivery shall consist of group A inspection.

4.6.1 Inspection lot. An inspection lot shall consist of all category I and category II switches of the same
specification sheet, of the same enclosure requirement, temperature characteristic and interface and
dimensions, produced under essentially the same conditions and offered for inspection at one time. Similar
switches conforming to these requirements but having different circuitry may be combined to form a lot.

4.6.2 Group A inspection, Group A inspection shall consist of the inspections specified in table III. The
inspection may be performed in any order.

4.6.2.1 Sampling plan. Statistical sampling shall be in accordance with table III and IV. A randomly selected
group(s) of samples is required for subgroup 1 and subgroup 2. For acceptance of the lot, there shall be zero
occurrences of defects.

4.6.2.1.1 Subgroup 1. A sample of parts shall be randomly selected in accordance with table IV, subgroup 1
sampling plan.

4.6.2.1.2 Subgroup 2. A sample of parts shall be randomly selected in accordance with table IV, subgroup 2
sampling plan.

4.6.2.2 Rejected lots. If an inspection lot is rejected, the lot shall be 100 percent inspected for the defects
noted. The contractor may correct the defects or remove all of the defective units from the lot. The lot shall then
be sampled again in accordance with tables III and IV. For acceptance, there shall be zero occurrences of
defects. If one or more defects are found in the second sample, the lot shall be rejected and shall not be
supplied to this specification. Such lots shall be separate from new lots and shall be clearly identified as
reinspected lots.

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TABLE I. Qualification test sequence.

2 Switches for
Inspection Requirement Test Specimen each voltage,
paragraph paragraph current
1 2 3 4 5 6 7 8 9 10 11 and frequency
Visual, mechanical
3.1 4.7.1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
examination
Solderability 3.6.1 4.7.2 2
Resistance to
3.6.2 4.7.3 2
soldering heat
Switching 2
3.6.3 4.7.4 2 2 2 2 2 3 2 2 2 2 2
Characteristics
Strength of Terminals
3.6.4 4.7.5 3
1/
Strength of toggle
lever, pivot and lever 3.6.5 4.7.6 4
stop 1/
Strength of mounting
3.6.6 4.7.7 5
bushing 1/
Contact voltage drop 3.6.7 4.7.8 3 3 6 3 3
Dielectric withstand.
3.6.8 4.7.9 7 4 4
voltage
Mechanical endurance 3.6.9 4.7.10 4 4
Electrical overload,
electrical endurance,
intermediate current 4.7.11 8 5 5
and temperature rise

Overload circuit 3.6.10 4.7.11.1 9

Resistive load 4.7.11.2 6
Inductive load 4.7.11.3 6
Lamp load 4.7.11.4 3
Intermediate current 4.7.11.5
Temperature rise 4.7.11.6 10
Contact voltage drop 3.6.7 4.7.8 5 5
Short circuit 3.6.11 4.7.12 3 3
Vibration 3.6.12 4.7.13 3 3
Shock 3.6.13 4.7.14 4 4
Salt spray (corrosion) 3.6.14 4.7.15 4 4
Thermal shock 3.6.15 4.7.16 3 4
Moisture resistance 3.6.16 4.7.17 5 5 4 5
Dielectric withstand.
3.6.8 4.7.9 6 6 5 6 11 7 7
voltage
Sand and dust 3.6.17 4.7.18 2 2
Explosion 3.6.18 4.7.19 3 3
Visual, mechanical 4
3.1 4.7.1 7 7 5 5 6 7 6 6 4 4 12 8 8
examination
Switching 5
3.6.3 4.7.4 8 8 6 6 7 8 7 7 5 5 13 9 9
characteristics
Toggle seal 2/ 3.6.19 4.7.20 9 9 7 7 8 9 8 8 6 6 14 10 10 6
Terminal sealing (when
3.6.20 4.7.21 10 10
applicable) 2/

1/ Test shall be performed on two specimens only.

2/ Only the odd-numbered specimens shall be opened by the manufacturer.

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TABLE II. Group submission for qualification inspection for complete listing.

Additional switches Additional switches

Basic switch (Visual and mechanical Basic switch (Visual and mechanical
(all applicable tests) examination and (all applicable tests) examination and switching
switching characteristics) characteristics)
MS25068-21 MS25068-24 MS27746-21 ----
MS25068-27 MS25068-28 MS27746-27 ----
MS25098-23 ---- MS27747-21 ----
MS25098-29 ---- MS27747-27 ----
MS25100-23 ---- MS27753-1 ----
MS25100-29 ---- MS27753-6 ----
MS25125-1 MS25125-4 MS27754-1 ----
MS25125-7 MS25125-8 MS27754-6 ----
MS25126-1 MS25126-4 MS27790-1 ----
MS25126-7 MS25126-8 MS27790-6 ----
MS25127-1 MS25127-4 MS35058-21 MS35058-24
MS25127-7 MS25127-8 MS35058-27 MS35058-28
MS25201-4 ---- MS35059-21 MS35059-24
MS25201-6 ---- MS35059-27 MS35059-28
MS27716-21 ---- MS75028-21 ----
MS27716-27 ---- MS75028-27 ----
MS27717-21 ---- MS75029-21 ----
MS27717-27 ---- MS75029-27 ----
MS27718-21 ---- MS75075-1 MS75075-4
MS27718-27 ---- M83731/1-21 ----
MS27719-21 ---- M83731/1-27 ----
MS27719-27 ---- M83731/2-21 ----
MS27720-21 ---- M83731/2-27 ----
MS27720-27 ---- M83731/3-21 ----
MS27721-21 ---- M83731/3-27 ----
MS27721-27 ---- M83731/4-21 ----
M83731/4-27 ----

TABLE III. Group A inspection

Inspection Requirement Test method Sampling plan

paragraph paragraph 1/
Subgroup 1 See 4.6.2.1.1
Visual and mechanical 3.1 4.7.1
examination
Material 3.4 4.7.1
Design and Construction 3.5 4.7.1
Marking 3.7 4.7.1
Workmanship 3.9 4.7.1
Subgroup 2 See 4.6.2.1.2
Switching characteristics 3.6.3 4.7.4
Dielectric withstanding voltage 3.6.8 4.7.9
Contact voltage drop 3.6.7 4.7.8

1/ At the option of the contractor, documented in-process inspection may be used to satisfy the
requirements provided that all of the contractor’s in-process control data on these tests are made
available to the Government upon request.

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TABLE IV. Zero defect sampling plan.

Lot size Minimum number of switches to be

tested
Subgroup 1 Subgroup 2
1-8 5 All
9 - 15 5 13
16 - 25 5 13
26 - 50 5 13
51 - 90 7 13
91 - 150 11 13
151 - 280 13 20
281 - 500 16 29
501 - 1,200 19 34
1,201 - 3,200 23 42
3,201 - 10,000 29 50
10,001 - 35,000 35 60

4.6.3 Periodic inspection. Periodic inspection shall consist of group B. Except where the results of these
inspections show noncompliance with the applicable requirements (see 4.6.3.1.4), delivery of products which
have passed group A shall not be delayed pending the results of these periodic inspections.

4.6.3.1 Group B inspection. Group B inspection shall consist of the inspections specified in table V, in the
order shown. When a manufacturer has switches qualified under various MS military standards or military
specification sheets, the qualifying activity may authorize group B tests that do not require redundant testing on
similar features. Group B inspection shall be performed on sample units selected from inspection lots which
have passed group A inspection. A manufacturer’s normal quality control tests, production tests, environmental
tests and so forth may be used to fulfill all or part of group B inspection; however, all of group B inspection shall
be completed as specified in table V. Data used may be accumulated within the previous 24 months.

4.6.3.1.1 Sampling plan. Group B inspections shall be completed in accordance with table V within 36
months after the date of notification of qualification and within each subsequent 36 month period. The sample
units shall be selected either from stock or a current production lot unless the Government considers it more
practical to select a sample from current production. Switches selected from stock shall have been produced
after the date of notification of qualification or subsequent to the date code of the previous group B inspection
sample units. Group B inspection shall be performed on sample units produced using the same manufacturing
facilities and processes as units normally offered for acquisition. When there has been no production of a
particular type of switch for 36 months or more, sample units shall be selected from the next production lot
presented for acceptance and for each subsequent 36 month period. When the specification sheet covers more
than one part number, the part number subjected to group B inspection shall be the same part number specified
for qualification; however, the group B inspection sample unit(s) need not be submitted to inspections not
specified for qualification.

4.6.3.1.2 Failures. If one or more sample units fails to pass group B inspection, the sample shall be
considered to have failed.

4.6.3.1.3 Disposition of sample units. Sample units subjected to group B inspection shall not be delivered on
the contract or order but shall be kept on hand until the next inspection period for submittal to the qualifying
activity if so requested.

4.6.3.1.4 Noncompliance. If a sample fails to pass group B inspection, the contractor shall notify the
qualifying activity and the cognizant inspection activity of such failure and take corrective action on the materials
or processes, or both, as warranted and on all units of product which can be corrected and which were
manufactured under essentially the same conditions, with essentially the same materials, processes and so
forth, and which are considered subject to the same failure. Acceptance of the product shall be discontinued
until corrective action, acceptable to the government has been taken. After the corrective action has been taken,
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group B inspection shall be repeated on additional sample units (all inspections or the inspection which the
original sample failed, at the option of the government). Group A inspection may be reinstated; however, final
acceptance shall be withheld until the group B reinspection has shown that the corrective action was successful.
In the event of failure after reinspection, information concerning the failure and the corrective action taken shall
be furnished to the contracting officer and the qualifying activity.

TABLE V. Group B inspection.

Requireme Test Specimen

nt
Inspection paragraph paragrap 1 2 3 4 5 6 7 8 9 10 11 12
h
Solderability 3.6.1 4.7.2 x x
Strength of mounting 3.6.6 4.7.7 4/ x x
bushing
Mechanical endurance 3.6.9 4.7.10 x x
Electrical overload, electrical
endurance, intermediate
current and temperature rise 3.6.10 4.7.11
Overload circuit 4.7.11.1 x x x x
Resistive load (ac) 1/ 4.7.11.2 x x
Inductive load (altitude) 2/ 4.7.11.3 x x
Temperature rise 4.7.11.6 x x
Contact voltage drop 3.6.7 4.7.8 x x
Shock 3.6.13 4.7.14 x x
Salt spray (corrosion) 3.6.14 4.7.15 x x
Moisture resistance 3.6.16 4.7.17 x x
Dielectric withstanding 3.6.8 4.7.9 x x x x
voltage
Visual and mechanical 3.1 4.7.1 x x x x x x x x x x x x
examination
Switching Characteristics 3.6.3 4.7.4 x x x x x x x x x x
Toggle seal 3/ 3.6.19 4.7.20 x x x x x x x x x x

1/ Test at 115 volts, 60 Hz, 71°C.

2/ Test at 28 V dc, 65,000 feet.
3/ Only the odd-numbered specimens shall be opened by the manufacturer.
4/ Torque shall be applied to the switch body only.

4.7 Methods of inspection and test.

4.7.1 Visual and mechanical examination. Switches shall be examined to verify that the materials, physical
dimensions, marking and workmanship are in accordance with the applicable requirements. Only two of the
sample units shall be inspected for compliance with physical dimensions. The inspection shall be performed
before any other test is performed on the sample units (see 3.1, 3.4 and 3.5).

4.7.2 Solderability (applicable to solderable terminals, see 3.6.1). Switches shall be tested in accordance
with method 208 of MIL-STD-202. The following details and exception shall apply:

(a) Number of terminals to be tested - A minimum of one terminal of a closed contact per switch.
(b) Depth of immersion in molten solder - Terminals shall be immersed to the maximum extent possible.
(c) Examination of terminals - Method for evaluation of lugs and tabs shall apply.
(d) Dipping machine - Need not be used.

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4.7.3 Resistance to soldering heat (applicable to solderable terminals, see 3.6.2). Switches shall be tested
in accordance with method 210 of MIL-STD-202. The following details shall apply:

(a) Number of terminals to be tested - A minimum of one terminal of a closed contact per switch.
(b) Depth of immersion in molten solder - Terminals shall be immersed to the maximum extent possible.
(c) Test condition letter - B
(d) Cooling time prior to final examinations and measurements - Not applicable.
(e) Examinations and measurements:
(1) Before - None.
(2) After - Switches shall be operable and there shall be no evidence of internal deformation or
other damage when opened at the conclusion of the test sequence.

4.7.4 Switching characteristics (see 3.6.3). Switching action (e.g., on-off, on-off-on, and so forth) and
circuitry shall be inspected for compliance with the applicable requirements (see 3.1). Circuit continuity shall be
inspected using a maximum load of 6 volts dc, 100 milliamperes.

4.7.5 Strength of terminals (see 3.6.4). Switches shall be mounted by their normal mounting means. Two
terminals on each switch shall be tested (see figure 1). However, a terminal shall be tested only once in one
direction.

4.7.5.1 Solderable terminals. Solderable terminals shall be tested in accordance with method 211 of MIL-
STD-202. The following details and exceptions shall apply:

(a) Test condition letter - A.

(b) Applied force - 5 pounds.
(c) Direction of applied force -
(1) With the terminals vertical and pointing downward, the specified pull shall be applied directly
downward.
(2) With the terminals horizontal, the specified pull shall be applied directly downward.

4.7.5.2 Screw-lug terminals. Screw-lug terminals shall be tested in accordance with method 211 of MIL-
STD-202. The following details and exceptions shall apply:

(a) Test condition letter - A.

(b) Applied force - 25 pounds, except that where 4-40 terminals are used, a 5 pound pull shall be used.
(c) Direction of applied force -
(1) Parallel to the axis of the terminal screw.
(2) Perpendicular to the axis of the terminal screw.

4.7.5.3 Integrated wire terminals. Integrated wire terminals shall be subjected to a 15 pound pull, except 5
pound pull for miniature switches, for 5 to 10 seconds in the following directions:
(a) Two outboard terminals on each switch shall be tested; however, a terminal shall be tested only
once in one direction.
(b) With the long dimensions of the terminal contact vertical and the contact opening facing downward,
the specified pull shall be applied directly downward.
(c) With the long dimension of the terminal contact horizontal, the specified pull shall be applied directly
downward.

4.7.5.4 Screw-thread terminals. Screw-thread terminals shall be tested in accordance with method 211 of
MIL-STD-202, test condition letter E. The torque shall be applied in a direction which will tighten the screw.

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4.7.6 Strength of toggle lever, pivot and lever stop (see 3.6.5). The switch shall be operated mechanically
and electrically at a maximum load of 6 volts dc, 100 milliamperes after the following tests:

(a) A 25 pound load shall be applied to the tip of the actuating lever for 1 minute under each of the
following conditions:
(1) Perpendicular to the lever axis and parallel to the line of lever travel at each end position of
the lever. For lever-lock types, the test shall be conducted at each fixed position of the
lever.
(2) Perpendicular to the lever axis and perpendicular to the line of travel at each lever position.
(3) Coaxial with the lever axis away from the lever pivot, throughout the entire range of lever
travel.
(b) A 15 pound load shall be applied to the tip of the actuating lever, coaxial with the lever axis and
toward the lever pivot, throughout the entire range of lever travel. For lever-lock types, this test is
only applicable to those changes in lever position which may be accomplished without lifting the
lever from its detent position.
4.7.7 Strength of mounting bushing (see 3.6.6). Bushing-mounted switches shall be mounted on a metal
panel using normal mounting means and hardware. A torque of 25-pound-inches shall be applied to the
mounting nut on switches with 15/32-inch diameter bushings or larger and a torque of 15-pound-inches shall be
applied to the mounting nut on smaller size bushings. With the mounting nut tightened using a maximum torque
of 5-ounce-inches, a torque of 5-pound-inches shall then be applied to the mounted switch body.

4.7.8 Contact voltage drop (3.6.7). Switches shall be tested in accordance with method 307 of MIL-STD-
202. The following details and exceptions shall apply:

(a) Measurements shall be made between the terminals of the contacts of the same pole forming a
switching circuit. Measurements shall be made for each pole of multiple pole switches.
(b) Test current - 100 milliamperes.
(c) Open-circuit voltage - 2 to 6 volts dc.
(d) Number of activation’s prior to measurement - Three.
(e) Number of test activation’s - Three.
(f) Number of measurements per activation - One.

4.7.9 Dielectric withstanding voltage (see 3.6.8). Switches shall be tested in accordance with method 301 of
MIL-STD-202. The following details and exceptions shall apply:

(a) Special conditions - For qualification and group B inspections, switches shall be tested in
accordance with 4.7.9.1 and 4.7.9.2. For group A inspection, switches shall be tested in accordance
with 4.7.9.1.
(b) Test voltage - The magnitude of the applied test voltage shall be as specified in 4.7.9.1 and 4.7.9.2.
(c) Duration of application of test voltage -
(1) Qualification and group B inspections - 1 minute minimum.
(2) Group A inspection - 2 to 5 seconds.
(d) Points of application - The following points of application shall apply for each toggle lever position:
(1) Between current-carrying parts and all uncommon exposed or grounded metal parts.
(2) Between current-carrying parts of adjacent poles of multipole switches (not applicable after
electrical endurance tests).
(3) Between mutually insulated current-carrying parts of the same pole (not applicable after
electrical endurance tests).
(e) Monitoring - The circuit shall be continuously monitored during the application of the test voltage to
determine if the leakage current exceeds 500 microamperes.
(f) Examination after test - Switches shall be examined for evidence of arcing, flashover, breakdown of
insulation or damage.

4.7.9.1 At atmospheric pressure. The applied test voltage shall be:

(a) Qualification and group B inspections - 1,000 Vrms minimum except:
(1) Switches rated above 250 volts shall be subjected to a minimum voltage of 1,000 Vrms plus
200 percent of the maximum rated voltage.
(2) 750 Vrms minimum after electrical endurance.

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(b) Group A inspection - Test shall be conducted at room ambient conditions and the potential shall be
1,200 Vrms minimum except switches rated above 250 volts shall be subjected to a minimum
voltage of 1,200 Vrms plus 240 percent of the maximum rated voltage.

4.7.9.2 At reduced barometric pressure. The following details shall apply:

(a) Method 105 of MIL-STD-202 at 65,000 feet.

(b) The applied test voltage shall be 500 Vrms minimum except switches rated above 250 Vrms shall be
subjected to a minimum voltage of 500 Vrms plus 200 percent of the maximum rated voltage.

4.7.10 Mechanical endurance (see 3.6.9). Unless otherwise specified (see 3.1), the switches shall be
subjected to 40,000 cycles of operation the following details shall apply:

(a) One half of the cycles shall be at -65° +0°/-4°C, while the other half of the cycles shall be at +71°
+4°/-0°C.
(b) A cycle shall be the movement of the toggle lever from one extreme position to the other extreme
position and return to the original position.
(c) Cycling rate shall be 10 to 18 cycles per minute (cpm). At the manufacturer’s option, a faster rate of
cycling, up to 60 cpm may be used.
(d) Lever-lock switch handles shall also be tested for 20,000 actuation’s at room ambient conditions by
pulling the lever to its fully extended position and then permitting it to return to its fully retracted
position without operation of the switches, at a maximum of 60 cpm.
(e) With the toggle lever in the unlocked position, lever-lock switches shall be tested with the toggle
lever moving through all positions.
(f) Momentary switches shall return from their momentary position(s) solely by the internal mechanism
of the switch.

4.7.11 Electrical endurance, electrical overload, intermediate current and temperature rise (see 3.6.10). The
following details shall apply:

(a) Test switches shall be mounted by their normal mounting means against a metal plate. Insulators
shall not be interposed between the switch case and the metal plate or between the metal actuator
of the actuating machine and the switch toggle.
(b) The metal mounting plate, one side of the power supply and the metal actuator of the actuating
machine shall all be connected to a common ground through a 3 ampere fuse per MIL-PRF-
15160/2, characteristic A, (F02A, 250V, 3A) (see figure 2). For dc, the negative side of the power
supply shall be grounded. The test switch shall be connected to the power source and test load
using a 1/2 to 6 feet length of wire as specified in table VI.
(c) The test voltage magnitude and electrical frequency shall be maintained within the tolerances
specified when the test voltage is measured at the switch terminals. Each operation of the switch
shall be monitored to determine whether any contact has failed to open or close its individual circuit
in proper sequence. Each failure shall be recorded and reported. Monitoring circuits shall not shunt
switch contacts or inductive components in the test circuit.
(d) One throw of each pole of the switch shall be connected to an independent test circuit meeting the
specified conditions. Multipole switches are to be tested with a load per pole and with opposite line
polarity on adjacent poles in accordance with figure 2. For double-throw switches, one half of the
switches shall be tested with the load circuit connected to one throw and the remaining half of the
switches shall be tested with the load circuit connected to the other throw.
(e) Switches shall be actuated at a frequency of 10 to 18 cpm and at a velocity of 3 to 5 inches per
second by a power driven actuator. The switch shall be actuated for the specified number of cycles
and shall be actuated only through the toggle lever positions necessary to make and break the test
load. At the option of the supplier, cycling may be interrupted periodically after each 5,000 cycles of
operation. Switches with lever lock toggle levers shall be tested with the toggle lever in the unlock
position.
(f) During the overload test, the closed time of the switch shall be 0.5 second minimum during each
cycle of operation. Unless otherwise specified (see 3.1), the endurance test duty cycle shall be a
minimum of 25 percent on.

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(g) Unless otherwise specified (see 3.1), two switches shall be subjected to the overload, resistive,
inductive and lamp load endurance tests at each voltage, current and frequency specified (see table
I).
(h) Overload and endurance tests shall be performed on the same pair of contacts, using the same
voltage and electrical frequency for both tests.

4.7.11.1 Overload circuit. The switch shall make and break 150 percent of the rated resistive load at the
applicable voltage and electrical frequency for 50 cycles of operation at room conditions.

4.7.11.2 Resistive load (dc and ac). One half of the switches shall make and break the rated resistive load
for 20,000 operating cycles at room ambient pressure and a temperature of 71° +4°/-0°C (or other temperature
as specified). The other half of the switches shall make and break the rated resistive load for 20,000 operating
cycles while at room temperature and a pressure equivalent to 65,000 feet altitude.

4.7.11.3 Inductive load (dc and ac). One half of the switches shall make and break the rated inductive load
for 20,000 operating cycles while at a pressure equivalent to 65,000 feet altitude and at room ambient
temperature while the other half shall make and break the rated inductive load for 20,000 operating cycles at
room ambient temperature and pressure. The dc inductive loads shall use inductors which have the response
and storage energy values as indicated on figure 3, figure 4 and figure 5. The ac inductive loads shall have a
power factor of 70 +5 percent.

4.7.11.4 Lamp load (dc and ac). Switches shall be subjected to 20, 000 operating cycles when wired into a
circuit having rated steady state lamp load current at the applicable rated voltage. For ac lamp loads, only
tungsten filament lamps having a wattage not exceeding 200 watts at the specified voltage shall be used to
make up the load. For dc lamp loads, only tungsten filament lamps having a wattage rating up to 50 watts at the
specified voltage shall be used to make up the load. A minimum cooling period of 15 seconds shall be allowed
between successive operations of the lamps. At the option of the manufacturer, a synthetic lamp load may be
used for this test. The synthetic lamp load shall consist of making 10 times the rated lamp load and breaking the
rated lamp load. The duration of the 10 times inrush shall be .015 seconds minimum.

4.7.11.5 Intermediate current. Switches shall be subjected to 20,000 operating cycles of making and
breaking a 35 to 40 milliampere resistive load at the lowest rated dc voltage in an ambient temperature of 71°
+4°/-0°C. Multipole switches shall be subjected to this test with alternate poles making and breaking the rated
resistive load at the lowest rated dc voltage.

4.7.11.6 Temperature rise. Each pole of the switch shall be connected in a circuit carrying the resistive
endurance test current at any convenient ac or dc voltage. At the end of a 1-hour period, the terminal
temperature rise at a point adjacent to the insulating medium shall be determined by means of appropriate
thermocouples consisting of No. 28-32 AWG iron-constantan wire. This test shall be performed on the same
switch contacts previously subjected to the overload and resistive electrical endurance test. During this test,
switches shall be mounted 6 inches apart in still air on a 1/16 inch thick steel panel at least 6 inches wide.

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“A” Metal mounting plate and metal actuator of actuating machine.

1/ See table VI for proper fuse or circuit breaker.

FIGURE 2. Test set-up for electrical test.

4.7.12 Short circuit (see 3.6.11). Switches shall be tested in accordance with 4.7.12.1, or 4.7.12.2 when
specified (see 3.1). The following details shall apply to both methods:
(a) The switches shall be inserted in a circuit calibrated to supply current equal to 60 times the rated
resistive load at the lowest rated dc voltage specified (see 3.1).
(b) The switches shall be connected in series to a thermal type circuit breaker or a fuse in accordance
with figure 3 and table VI.
(c) The wire shall be as specified in MIL-W-5086 and table VI, as determined by the rated resistive load
of the switch (see 3.1).
(d) Terminals shall be in accordance with SAE-AS7928.
(e) Calibration shall be made with a substitute circuit breaker (or fuse), with the switch being tested, and
with the switch leads in the circuit.
(f) The calibrated circuit shall be closed by the appropriate switch (see 4.7.12.1 or 4.7.12.2) and after
the circuit breaker or fuse interrupts the circuit, the appropriate switch shall be manually opened by
means of the toggle lever. This procedure shall be performed 10 times. After each closure, the
toggle lever of the switch under test shall be returned manually to the “OFF” or an alternate position,
and the switch contacts shall be checked for proper opening by any suitable continuity test method.
The circuit breaker shall be reset or the fuse replaced after each closure. Two minutes minimum
shall elapse between closures.
(g) For double through switches, one half shall be tested in one position and the other half shall be
tested in the other position. For multipole switches, any (one) pole shall be tested.

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TABLE VI. Wire size and circuit breaker or fuse designations.

Amperes 1/ MIL-W-5086 wire size Circuit breaker or fuse

3.0 or less 20
5.0 20
7.5 18
10.0 18
15.0 18
18.0 16 The size of the circuit breaker
20.0 16 or fuse shall be equivalent to
25.0 14 the test current.
30.0 14
40.0 12
60.0 10
80.0 8
175.0 2
1/ Where the wire size, circuit breaker or fuse size does not coincide with the
required current, the next larger wire size, circuit breaker or fuse shall be
used.

4.7.12.1 Method I. The switch used to calibrate the circuit shall close the circuit.

4.7.12.2 Method II. The switch being tested shall close the circuit.

FIGURE 3. Circuit diagram for short circuit test.

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FIGURE 4. Response (current versus time) type I inductors only.

FIGURE 5. Stored energy (joules versus current) type I inductors only.

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4.7.13 Vibration (see 3.6.12). Switches shall be tested in accordance with method 204 of MIL-STD-202.
The following details and exceptions shall apply:

(a) Contact chatter shall be monitored in accordance with method 310 of MIL-STD-202.
(b) Test condition letter - A.
(c) Tests and measurements prior to vibration - Not applicable.
(d) Mounting - Switches shall be rigidly mounted by their normal mounting means on a rigid metal panel.
The mounting fixture shall be free from resonances over the test frequency range. Half of the
switches shall be tested in one lever position and the other half of the switches shall be tested in the
alternate lever position.
(e) Electrical load conditions - The electrical load shall consist of the monitor circuit only.
(f) Measurements during vibration - Switch contact stability shall be continuously monitored during
vibration. If more than one contact pair is being monitored simultaneously by one chatter indicator,
open contact pairs shall be connected in parallel and closed contact pairs shall be connected in
series during this test. In the event of indication of a contact opening greater than specified, the test
shall be modified so that switches may be individually tested to determine if a switch is defective.
(g) Measurements after vibration - Switching characteristics (see 4.7.4).
(h) Examination after test - Switches shall be examined for change in actuated position and evidence of
broken, deformed, displaced or loose parts.

4.7.14 Shock (see 3.6.13). Switches shall be tested in accordance with 4.7.14.1, and in addition 4.7.14.2
when specified (see 3.1). The following details and exceptions shall apply to both methods:

(a) Contact chatter shall be monitored in accordance with method 310 of MIL-STD-202.
(b) Mounting - Switches shall be mounted by their normal mounting means. Half of the switches shall
be tested in one lever position and the other half of the switches shall be tested in the alternative
lever position.
(c) Electrical load conditions - The electrical load shall consist of the monitor circuit only.
(d) Measurements during shock - Switch contact stability shall be continuously monitored during shock.
If more than one contact pair is being monitored simultaneously by one chatter indicator, open
contact pairs shall be connected in parallel and closed contact pairs shall be connected in series
during this test. In the event of indication of a contact opening greater than specified, the test shall
be modified by applying successive identical blows in the same plane to monitor contacts, switch by
switch, to determine if a switch is defective.
(e) Measurements after shock - Switches shall be inspected for switching characteristics (see 4.7.4).
(f) Examination after test - Switches shall be examined for evidence of broken, deformed, displaced or
loose parts.

4.7.14.1 Method I.

(a) Method 213 of MIL-STD-202.

(b) Test condition - B.
(c) Allowable contact opening or closure - 10 microseconds maximum.

4.7.14.2 Method II.

(a) Method 207 of MIL-STD-202.

(b) Allowable contact opening or closure - 20 milliseconds maximum.

4.7.15 Salt spray (corrosion) (see 3.6.14). Switches shall be tested in accordance with method 101 of MIL-
STD-202. The following details and exceptions shall apply:

(a) Test condition letter - A.

(b) Switches shall be subjected to 10 cycles of operation using a 6 volt source and a maximum load of
100 milliamperes immediately following the wash.
(c) Switches shall be examined for warping, cracking or excessive corrosion. Excessive corrosion is
defined as corrosion which interferes with electrical or mechanical performance, or in the case of
plated metals, corrosion which has passed through the plating and attacked the base metal. After
the test, mounting hardware shall be readily removable.
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4.7.16 Thermal shock (see 3.6.15). Switches shall be tested in accordance with method 107 of MIL-STD-
202. The following details shall apply:

(a) Test condition letter - A.

(b) Measurements before and after cycling - Not applicable.
(c) Examinations after test - Switches shall be examined for mechanical and electrical damage and
loosening of rivets or other fastening devices.

4.7.17 Moisture resistance (see 3.6.16). Switches shall be tested in accordance with method 106 of MIL-
STD-202. The following details and exceptions shall apply:

(a) Mounting - By normal mounting means on a corrosion resistant metal panel positioned 15° from the
vertical. One half of the switches shall be mounted with the toggle lever up and the other half with
the toggle lever down. The mounting panel shall have appropriate mounting holes so that switches
are at least 1 inch apart.
(b) Polarization - During steps 1 to 6 inclusive, a dc potential of 100 volts shall be applied between
current-carrying parts and panel. Negative polarity shall be applied to the panel. Steps 7a and 7b
are not applicable.
(c) Final measurements - Following a 24 hour drying period at 25 +5°C and 50 +5 percent relative
humidity, switching characteristics shall be measured as specified in 4.7.4. Switches shall be
examined for evidence of breaking, spalling, cracking or loosening of terminals and shall be
electrically operable.
(d) Water - Steam, deionized or distilled water shall be used.

4.7.18 Sand and dust (see 3.6.17). Switches shall be tested in accordance with method 110 of MIL-STD-
202. The following details shall apply:

(a) The switches shall be oriented so that the toggle lever is exposed to the dust stream.
(b) During step 3, the switches shall be mechanically actuated for 2,500 cycles at a rate of 14 +4 cycles
per minute.
(c) Step 3 shall be performed immediately after reaching stabilization in step 2.
4.7.19 Explosion (see 3.6.18). Switches shall be tested in accordance with method 109 of MIL-STD-202.
The following detail shall apply:

(a) Electrical load - Switches shall be operated at their maximum rated dc inductive current (see 3.1). If
a dc inductive current is not specified, then the maximum dc resistive current shall be used.

4.7.20 Toggle seal (applicable only to toggle seal switches) (see 3.6.19). Switches with suitable removable
panel seals mounted behind the panel shall be mounted in the bottom of an open container. Tap water shall be
added to the container to obtain a depth of one-half inch above the top of the bushing. The switch bushing shall
remain submerged in water with the lever in any position for a period of 5 minutes. Then, while submerged, the
switches shall be operated through all lever positions for five complete cycles. The switches shall remain under
the one-half inch depth of water for an additional 5 minutes. The water shall then be removed from the container
and the switches shall be removed, opened and examined for evidence of leakage of water into the switches
due to entry through the toggle seal. Fixtures may be designed for testing more than one switch at a time.

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4.7.21 Terminal sealing, fluid submersion (applicable to switches with integrated wire terminals) (see
3.6.20).

(a) Applicable to qualification and group B only. Switch terminals shall be immersed for three cycles as
follows:
(1) Switches with integrated wire terminals shall be fully wired.
(2) Switch terminals shall be completely submerged in each of the following fluids for 2 +1/2, -0
minutes which shall consist of one cycle.
a. MIL-DTL-5624 - Turbine Fuel, Aviation, Grade JP-4 or JP-5.
b. Skydrol 500 A - National Stock Number 9150-857-9069.
c. MIL-PRF-87252 - Coolant Fluid, Hydrolytically Stable, Dielectric or equivalent.
d. ASTM E 1119 - Ethylene glycol.
e. MIL-PRF-7808 - Lubricating Oil, Aircraft Turbine Engine, Synthetic Base.
f. After each immersion, the excess liquid is to be blown off the switch external surfaces
with an air jet.
(3) At the end of the third cycle, the dielectric withstanding voltage shall be measured as
specified in 4.7.9.1. The switches shall be examined for evidence of cracking and loosening
of bonds and seams.

5. PACKAGING

5.1 Packaging. For acquisition purposes, the packaging requirements shall be as specified in the contract or
order (see 6.2). When actual packaging of material is to be performed by DoD personnel, these personnel need
to contact the responsible packaging activity to ascertain requisite packaging requirements. Packaging
requirements are maintained by the Inventory Control Point’s packaging activity within the Military Department
of Defense Agency, or within the Military Department’s System Command. Packaging data retrieval is available
from the managing Military Department’s or Defense Agency’s automated packing files, CD-ROM products or by
contacting the responsible packaging activity.

6. NOTES

(This section contains information of a general or explanatory nature that may be helpful, but is not
mandatory.)

6.1 Intended use. Switches furnished under this specification are intended for use in protected environments
having a minimum of moisture and contaminates. Unless otherwise specified on the individual MS military
standards or military specification sheets, the switches are not intended for use in circuits with ratings lower than
the intermediate current.

6.2 Acquisition requirements. Acquisition documents must specify the following:

a. Title, number, and date of the specification.

b. Issue of DODISS to be cited in the solicitation, and if required, the specific issue of individual
documents referenced (see 2.1).
c. Packaging requirements (see 5.1).

6.2.1 Category I switches (items covered by specification sheets or MS standards and identified by a part
number, see 3.2.1). Acquisition documents must specify the following:

a. Title, number and date of this specification.

b. Title, number and date of the applicable specification sheet or MS standard and the part number.
c. Issue of the DoDISS to be cited in the solicitation and if required, the specific issue of the individual
documents referenced (see 2.1).
d. Packaging requirements (see 5.1).
e. Type and amount of hardware to be included with the switch, if other than that specified on the
applicable specification sheets or MS standard.

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6.2.2 Category II switches (qualified switches with modification, see 3.2.2). Acquisition documents must
specify the following:

a. Title, number and date of this specification.

b. Title, number and date of the applicable specification sheet or MS standard and the part number.
c. Issue of the DoDISS to be cited in the solicitation and if required, the specific issue of the individual
documents referenced (see 2.1).
d. Packaging requirements (see 5.1).
e. Type and amount of hardware to be included with the switch, if other than that specified on the
applicable specification sheets or MS standard.
f. Switch is category II.
g. Part number of qualified switch.
h. Manufacturer’s part number of the modified switch (see 3.7.1(b)).
I. Details of the variations from the specification sheet or MS standard. A copy of the drawing furnished,
including the description of the variations from the specification sheet or MS standard, should be sent to
the Defense Supply Center Columbus, ATTN: DSCC-VAM, Post Office Box 3990, Columbus, OH
43216-5000.
j. Inspection requirements (in addition to group A): To verify suitability of variations from category I
switches. Available manufacturing data showing compliance may be substituted as meeting these
requirements at the option of the contracting activity.
(1) Tests to be performed (if any).
(2) The laboratory at which inspection is to be performed.
(3) Samples and submission of data, if other than that specified.
(4)
6.3 Qualification. With respect to products requiring qualification, awards will be made only for products
which are, at the time of award of contract, qualified for inclusion in the Qualified Products List QPL-83731
whether or not such products have actually been so listed by that date. The attention of contractors is called to
these requirements, and manufacturers are urged to arrange to have the products that they propose to offer to
the Federal Government tested for qualification in order that they may be eligible to be awarded contracts or
purchase orders for the products covered by this specification. The activity responsible for the Qualified
Products List is the Defense Supply Center Columbus, ATTN: DSCC-VQP, Post Office Box 3990, Columbus,
OH 43216-5000. Application for qualification tests should be made in accordance with “Provisions Governing
Qualification” (see 6.3.1).

6.3.1 Provision Governing Qualification. Copies of specifications and “Provisions Governing Qualification”
may be obtained upon application to Defense Printing Service Department Office, Building 4D (Customer
Service), 700 Robbins Avenue, Philadelphia, PA 19111-5094.

6.4 Luminescent tips. Luminescent material should conform to Type F of MIL-L-3891 (Luminescent Material
and Equipment, Non Radioactive).

6.5 Panel seal. Panel seals should be in accordance with MIL-B-5423/16 (Boot, Dust and Water Seal,
Bushing Seal, Type A).

6.6 Boots. Boots should be in accordance with MIL-B-5423 (Boot, Dust and Water Seal For Toggle and
Push-button Switches and Rotary-actuated Parts).

6.7 Switch guards. When switch guards are required, they should be in accordance with MIL-G-7703
(Guard, Switch).

6.8 Dissimilar metals (see 3.4.1.2). Dissimilar metals and compatible couples are defined in MIL-HDBK-
889.

6.9 Insulation (see 3.4.2).

6.9.1 Ceramic. It is recommended that MIL-I-10 Grade L422 be considered for ceramic materials.

6.9.2 Thermoplastic. It is recommended that thermoplastic materials be tested in accordance with MIL-M-
24519 to the requirements specified in 3.4.2.
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MIL-DTL-83731C

6.10 Rubber (see 3.4.3). It is recommended that rubber parts in accordance with ZZ-R-765 be considered
for use.

6.11 Potting compounds (see 3.4.4). It is recommended that potting compounds that meet the hydrolytic
stability requirements of MIL-S-8516, MIL-S-23586, MIL-M-24041 or MIL-I-16923 be considered for use.

6.12 Solder. It is suggested that ANSI/J-STD-002 be used for guidance only in dealing with solder.

6.13 Military standard part numbering. In order to provide uniform part number and format, MS27740
(Switches, MIL-S-3950 and MIL-S-83731, Military Standard Part Numbering) should be followed.

6.14 Part or Identifying Number (PIN). This specification requires a PIN that is as described in the
appropriate reference to associated documents (see 3.1).

6.15 Subject term (key word) listing.

Boots
Switch, guards
Switching, characteristics
Toggle, lever
Toggle, seal

6.16 Environmentally preferable material. Environmentally preferable materials should be used to the
maximum extent possible to meet the requirements of this specification. Table VII lists the Environmental
Protection Agency (EPA) top seventeen hazardous materials targeted for major usage reduction. Use of these
materials should be minimized or eliminated unless needed to meet the requirements specified herein (see
Section 3).

Table VII. EPA top seventeen hazardous materials.

Benzene Dichloromethane Tetrachloroethylene

Cadmium and Compounds Lead and Compounds Toluene
Carbon Tetrachloride Mercury and Compounds 1,1,1 - Trichoroethane
Chloroform Methyl Ethyl Ketone Trichloroethylene
Chromium and Compounds Methyl Isobutyl Ketone Xylenes
Cyanide and Compounds Nickel and Compounds

6.17 Changes from previous issue. Marginal notations are not used in this revision to identify changes with
respect to the previous issue due to the extensiveness of the changes.

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APPENDIX

Procedure for qualification inspection and mounting and terminal hardware.

10. SCOPE

10.1 This appendix details the procedure for submission of samples for qualification and group B inspection
of toggle switches covered by this specification. This appendix also lists mounting and terminal hardware
used with toggle switches covered by this specification. Mounting and terminal hardware should be of the
following design and construction as specified (see 31.).

20. SAMPLES

20.1 Qualification. For qualification inspection, the sample size shall be as specified in table I and the test
shall be performed in the sequence shown.

20.1.1 Single submission. A sample consisting of the required number of specimens of each switch shall be
submitted. Qualification shall be restricted to the type submitted.

20.1.2 Group submission. A sample consisting of the required number of specimens of each basic switch
listed in table II shall be submitted and shall be subjected to the qualification test sequence of table I in the
order shown. In addition, two specimens of each of the other switches listed in table II shall be submitted and
shall be subjected to the examination of product and switching characteristics test of
table I.

20.2 Group B inspection. Sample units shall be selected at random from lots that have passed group A
inspection.

20.2.1 Sample submission. The sample size shall be as specified in table V and the tests shall be
performed in the order shown.

20.2.2 Group submission. A sample consisting of the required number of specimens of each basic switch
listed in table V shall be subjected to the test sequence of table V in the order shown. In addition, two
specimens of each of the other switches listed in table II shall be submitted and shall be subjected to the
examination of product and switching characteristic test of table V. If the basic switches of a group are not in
production at the time of selection of samples, other switches of the same group may be submitted, but
maintained action switches shall not be substituted for momentary action switches.

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APPENDIX

30. MOUNTING HARDWARE

30.1 Nut, plain, hexagon, electrical, thin.

Threads A B C
Min Max Max Min ±.005
.250-40 UNS- .302 .313 .348 .361 .062
2B
.469-32 NS-2B .553 .564 .630 .651 .078
Material ASTM B16, alloy UNS C36000, half hard
Brass Finish Nickel plate QQ-N-290, class 1, grade G(matte) INCHES MM
MIL- hardware Can be replaced by MS25082-B14 (.250-40) .005 .13
MS25082-B8 (.468-32) .062 1.57
.078 1.98
Material FED STD No. 66,55,000 PSI (min sulphur or
.250 6.35
phosphorus shall not exceed 0.05 by weight .302 7.67
Steel Finish Suitably protected to resist corrosion .313 7.95
MIL hardware Can be replaced by MS25082-14 (.250-40) .348 8.84
MS25082-8 (.468-32) .361 9.17
Material FED STD No. 66 .468 11.89
Cres Finish Passivate .553 14.05
.564 14.33
MIL hardware Can be replaced by MS25082-C14 (.250-40) .630 16.00
MS25082-C8 (.468-32) .651 16.54

30.2 Washer, lock, flat, internal tooth.

INCHES MM
A B C .002 .05
.018 .46
.250 6.35
.256 6.50
Size Min Max Min Max ±.002 .267 6.78
.395 10.08
.250 .256 .267 .395 .410 .018 .410 10.41
.468 .472 .480 .593 .607 .018 .468 11.89
Material FF-W-100 .472 11.99
Steel Finish Suitably protected to resist corrosion .480 12.19
MIL hardware Can be replaced by AA55609-125 (.250 size) .593 15.06
AA55609-126 (.468 size) .607 15.42
Material FF-W-100

Cres Finish Passivate

MIL hardware Can be replaced by AA55609-135 (.250 size)

AA55609-136 (.468 size)

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APPENDIX

30.3 Washer, key. Inches mm

.005 .13
.024 .61
.034 .86
.037 .94
Bush A B C D E F G .043 1.09
.049 1.24
Dia .050 1.27
.049 .067 .226 .258 .408 .268 .034 .057 1.45
.250 .043 .057 .220 .252 .388 .258 .024 .059 1.50
.065 .115 .440 .480 .735 .397 .043 .065 1.65
.067 1.70
.468 .059 .105 .433 .470 .703 .387 .037 .105 2.67
Stee Material QQ-S-698 .115 2.92
l .220 5.59
.226 5.74
Finish Suitably protected to resist corrosion .250 6.35
MIL Can be replaced by MS25081-0 (.250 size) .252 6.40
hardware MS25081-4 (.468 size) .258 6.55
Cre Material FED STD No. 66 .268 6.81
.367 9.83
s .388 9.36
Finish Passivate .397 10.08
MIL Can be replaced by MS25081-C0 (.250 size) .408 10.36
.433 11.00
hardware MS25081-C4 (.468 size)
.440 11.18
.468 11.89
.470 11.94
.480 12.19
.703 17.86
.735 18.67

30.4 Washer, key “D”.

Inches mm
.024 .61
.034 .86
.045 1.14
.055 1.40
.057 1.45
.067 1.70
.230 5.84
Material QQ-S-698 .235 5.97
Steel Finish Suitably protected to resist corrosion .252 6.40
MIL-hardware None .258 6.55
.268 6.81
Material FED STD No.66 .388 9.86
Cres Finish Passivate .408 10.36
MIL hardware None

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APPENDIX

40. TERMINAL HARDWARE

40.1 Screw (pan head).

Thread A B
size Min Max Min Max
.138-32 UNC-2A .256 .270 .072 .062
.164-32 UNC-2A .306 .322 .085 .096 INCHES MM
Material ASTM B16, alloy UNS C36000 .031 .79
Brass Finish Silver plate, tin plate or nickel plate .072 1.83
QQ-N-290, class 1, grade G (matte) .082 2.08
MIL hardware None .085 2.16
Material FED STD No. 66, 55, 000 PSI (min sulphur or .096 2.44
phosphorus shall not exceed 0.05 by weight) .138 3.51
Steel Finish Suitably protected to resist corrosion .164 4.17
MIL hardware Can be replaced by MS35206-226 (.138-32) .250 6.35
MS35206-241 (.164-32) .256 6.50
Material FED STD No. 66 .270 6.86
Cres Finish Passivate .306 7.77
MIL hardware Can be replaced by MS51957-26 (.138-32) .322 8.18
MS51957-41 (.164-32)

Inches mm
40.2 Screw with captive internal tooth lockwasher. .016 .41
.018 .46
.020 .51
.022 .56
.071 1.80
.085 2.16
.087 2.21
.096 2.34
Thread .138 3.51
size A B C D E .164 4.17
.138-32 UNC- .260 .295 .290 .087 .020 .219 5.56
2A .219 .285 .256 .071 .016 .250 6.35
.164-32 UNC- .250 .338 .322 .096 .022 .256 6.50
2A .219 .327 .306 .085 .018 .260 6.60
Screw Material ASTM B16, alloy UNS C36000 .265 6.73
(Brass) Finish Silver or tin plate .290 7.37
MIL None .295 7.49
hardware .306 7.77
Lockwasher Material ASTM B139, alloy UNS C51000 .322 8.18
(Phos Finish Silver or tin plate .327 8.31
bronze) .338 8.59
MIL None
hardware

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APPENDIX

40.3 Washer, lock-spring, helical series.

Size A B C
Min Max Max Min Max
.138 .141 .151 .253 .031 .037
.164 .168 .178 .296 .040 .046
Material QQ-S-700 Inches mm
Steel Finish Suitably protected to resist corrosion .031 .79
MIL hardware Can be replaced by MS35338-41 (.138) .037 .94
MS35338-42 (.164) .040 1.02
Material FED STD No. 66 .046 1.17
Cres Finish Passivated .138 3.51
MIL hardware Can be replaced by MS35338-155 (.138) .141 3.58
MS35338-156 (.164) .151 3.84
.164 4.17
Material ASTM B139, alloy UNS C51000 .168 4.27
Bronze Finish Suitably protected to resist corrosion .178 4.52
MIL hardware Can be replaced by MS35338-98 (.138) .253 6.43
MS35338-99 (.164) .296 7.52

NOTES:
1. The captive internal tooth lockwasher on the terminal screw shall rotate freely.
2. The terminal screws with the captive internal tooth lockwasher shall be threaded to within .024 of the
lockwasher.
3. The terminal screw (pan head) shall be used in conjunction with the helical series lock-spring washer.
4. Dimensions are in inches.
5. Metric equivalents (to the nearest .01 mm) are given for general information only and are based upon
1.00 inch = 25.4 mm.

Custodians: Preparing activity:

Army - CR DLA - CC
Navy - AS
Air Force - 11 (Project 5930-1800)
DLA - CC

Review activities:
Army - AR, AV, MI
Navy - EC, MC

NOTE: The activities listed above were interested in this document as of the date of this document. Since
organizations and responsibilities can change, you should verify the currency of the information above using
the ASSIST Online database at www.dodssp.daps.mil.

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