ENGINEERING STANDARD

ES 2013 REV C
MAGNETIC PARTICLE TESTING ACCEPTANCE CRITERIA

ENGINEERING STANDARD
MAGNETIC PARTICLE TESTING ACCEPTANCE CRITERIA
FOR

ES 2013
 ENGINEERING STANDARD
ES 2013 REV C
MAGNETIC PARTICLE TESTING ACCEPTANCE CRITERIA

REVISIONS

REVISIONS DATE DESCRIPTION APP. BY

- 12-27-90 Release JM

A 07-16-96 Revised entire procedure and incorporated accept/reject JM

criteria from MIL-STD-1907.
SEE ECN 9170.
B 05/08/2000 Added Para 5.3 and Para 5.4 BL
ECN 12762
C 12/12/07 See ECN 20724 JM

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 ENGINEERING STANDARD
ES 2013 REV C
MAGNETIC PARTICLE TESTING ACCEPTANCE CRITERIA

1.0 Scope
This procedure is intended for use by Tactair and/or its suppliers when performing magnetic
particle inspection per ASTM-E1444 on products to be used in hydraulic actuator and valve
assemblies.

2.0 Magnetic Particle System

The magnetic particle system shall be as defined in ASTM-E1444 unless otherwise stated on the
component drawing or purchase order.

3.0 Written Procedure

3.1 The supplier shall perform all magnetic particle inspections to a specific written procedure,
prepared by the supplier, that implements the requirements of ASTM-E1444 for the
components under test.

3.2 The written procedure (s) shall contain the process information required by Sections 5.4 of
ASTM-E1444.

4.0 Inspection Of Parts

4.1 Inspection of all component parts under this procedure shall be done in accordance with
the approved written procedure and ASTM-E1444.

4.2 Examine all surfaces of parts except small openings that could entrap or remain
contaminated with inspection media unless otherwise specified on the drawing. These
areas shall be masked or plugged prior to inspection. Establish definite inspection
patterns, particularly when inspecting quantities of the same or similar parts, to ensure
examination of internal and external surfaces. Unless otherwise specified, 100 percent of
lot shall be inspected. All indications shall be identified with a marking pencil for further
review.

4.3 The following Tables I, II and III list the maximum size and distribution of discontinuities in
castings, wrought products and weldments:

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 ENGINEERING STANDARD
ES 2013 REV C
MAGNETIC PARTICLE TESTING ACCEPTANCE CRITERIA

Table I Castings
Maximum Allowable Discontinuity Sizes (In Inches) And Distribution

TYPE DISCONTINUITY GRADE A GRADE B GRADE C

Nonmetallic inclusion, rounded: Surface 0.031 Dia 0.047 Dia 0.063 Dia
D-3* D-3* D-3*

Subsurface 0.047 Dia 0.063 Dia 0.094 Dia

D-3* D-3* D-3*
Gas hole porosity/discrete Shrinkage cavities:
Surface 0.031 Dia** 0.047 Dia** 0.063 Dia**
D-3* D-3* D-3*

Subsurface 0.047 Dia** 0.063 Dia** 0.094 Dia**

D-3* D-3* D-3*
Cracks, hot tears, or 0 0 0
Cold shuts
Shrinkage sponge areas
(May include small cavities, cavity stringers) 0.250 0.375 0.625

Microshrinkage
(micro porosity)
Maximum cluster diameter: 0.063 0.188 0.313
D-3* D-3* D-3*
Alloy or metallic phase segregation
Surface: 0.125 0.375 1.5

Subsurface: 0.25 0.5 1.5

∗ Distribution designations signify the following:

D-2 Discontinuities no closer to each other than two times the maximum size.

D-3 Discontinuities no closer to each other than three times the maximum
size.

** The limits for gas hole porosity for the individual grades do not apply if the voids are
less than one half the maximum sizes specified and are well dispersed.

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 ENGINEERING STANDARD
ES 2013 REV C
MAGNETIC PARTICLE TESTING ACCEPTANCE CRITERIA

Table II Wrought Products

Maximum Allowable Discontinuity Sizes (In Inches) and Distribution (Excluding Weldments)

TYPE DISCONTINUITY GRADE A GRADE B GRADE C

Inclusions, rounded:
Surface 0.031 Dia 0.047 Dia 0.063 Dia
DD-2* D-3* D-3*

Subsurface 0.047 Dia 0.063 Dia 0.094 Dia

DD-2* D-3* D-3*
Inclusions, stringers:
Surface 0.125 Long 0.375 Long 0.75 Long
DD-1* DD-1* DD-1*

Subsurface 0.187 Long 0.5 Long 1.125 Long

DD-1* DD-1* DD-1*
Seams or laps 0.5 Long 1 Long 1.5 Long
(Unmachined surfaces) DD-1* DD-1* DD-1*
Seams or laps 0 0 0.25 Long
(Machine surfaces) DD-1*
Propagating discontinuities
(Cracks, flakes, laminations, etc.) 0 0 0
∗ Distribution designations signify the following:

D-3 Discontinuities no closer to each other than three times the

maximum size.
DD-1 Discontinuities no closer to each other than 0.5 inch linearly and
0.25 inch in a parallel direction.
DD-2 No more than two indications

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 ENGINEERING STANDARD
ES 2013 REV C
MAGNETIC PARTICLE TESTING ACCEPTANCE CRITERIA

Table III Weldments

Maximum Allowable Discontinuity Sizes (In Inches) and Distribution

TYPE DISCONTINUITY GRADE A GRADE B GRADE C

Cracks, weld or base metal (longitudinal,
transverse, star or crater, underbead, 0 0 0
underside, etc.)
Weld undercutting or lack of bead-edge
fusion:
Base metal less than 0.188 inch thick 0.016 Deep 0.016 Deep 0.031 Deep
0.125 Long 0.250Long 0.250 Long
D-5* D-5* D-5*

Base metal 0.188 inch thick and over 0.031 Deep 0.031 Deep 0.047 Deep
0.125 Long 0.250 Long 0.375 Long
D-5* D-5* D-5*
Weld metal voids or inclusions, rounded:
Base metal less than 0.188 inch thick: 0.016 Dia 0.031 Dia 0.063 Dia
D-5* D-5* D-5*

Base metal 0.188 inch thick and over: 0.031 Dia 0.063 Dia 0.125 Dia
D-5* D-5* D-5*
Weld metal voids or inclusions, elongated:
Base metal less than 0.188 inch thick: 0.063 Long 0.125 Long 0.188 Long
D-5* D-5* D-5*

Base metal 0.188 inch thick and over: 0.125 Long 0.250 Long 0.375 Long
D-5* D-5* D-5*

∗ Distribution designations signify the following:

D-5 Discontinuities no closer to each other than five times the maximum
dimension.

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 ENGINEERING STANDARD
ES 2013 REV C
MAGNETIC PARTICLE TESTING ACCEPTANCE CRITERIA

5.0 Accept/Reject Criteria

5.1 Within the specified grade, discontinuities exceeding the limits in Tables I, II and III shall
be rejected. Parts that have indications which are obviously rejectable shall be rejected,
tagged and dispositioned as appropriate. Parts that have questionable indications shall
be separated, tagged and processed for further evaluation.

5.2 When magnetic particle inspection is specified without the acceptance criteria being
defined, the minimum grade shall be "C" from Tables I, II and III.

5.3 Nonrelevant indications. Parts shall not be rejected because of incidental concentrations
of magnetic particles in areas which are not defective. Nonrelevant indications may
appear on fillets, weld beads, or other areas, particularly if there is surface roughness.

5.4 The appearance of indications due to micro segregations shall not be cause for rejection.
Micro segregations are extremely narrow lines, usually long and straight, on surfaces of
highly finished parts made of wrought metals. These indications are not considered
harmful when there are no physical indications i.e. cracks, stringer, etc…visible under 5X
magnification.

6.0 Cleaning After Magnetic Particle Inspection

6.1 Final cleaning after inspection shall be performed to remove all residues. Pay close
attention to internal cavities i.e.: drilled passages.

6.2 Parts shall be preserved after cleaning to prevent corrosion.

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