American Association

Designation: A 325 – 04 State Highway and

Transportation Officials
Standard AASHTO No.: M 164

Standard Specification for

Structural Bolts, Steel, Heat Treated, 120/105 ksi Minimum
Tensile Strength1
This standard is issued under the fixed designation A 325; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.

This standard has been approved for use by agencies of the Department of Defense.

1. Scope* standard does not purport to address all of the safety concerns,
1.1 This specification2 covers two types of quenched and if any, associated with its use. It is the responsibility of the user
tempered steel heavy hex structural bolts having a minimum of this standard to establish appropriate safety and health
tensile strength of 120 ksi for sizes 1.0 in. and less and 105 ksi practices and determine the applicability of regulatory limita-
for sizes over 1.0 to 11⁄2 in., inclusive. tions prior to use.
1.2 The bolts are intended for use in structural connections. 2. Referenced Documents
These connections are covered under the requirements of the
Specification for Structural Joints Using ASTM A 325 or A 490 2.1 ASTM Standards: 4
Bolts, approved by the Research Council on Structural Con- A 153 Specification for Zinc Coating (Hot-Dip) on Iron and
nections, endorsed by the American Institute of Steel Construc- Steel Hardware
tion and by the Industrial Fastener Institute.3 A 194/A 194M Specification for Carbon and Alloy Steel
1.3 The bolts are furnished in sizes 1⁄2 to 11⁄2 in., inclusive. Nuts for Bolts for High Pressure or High Temperature
They are designated by type, denoting chemical composition as Service, or Both
follows: A 449 Specification for Quenched and Tempered Steel
Type Description
Bolts and Studs
A 490 Specification for Structural Bolts, Alloy Steel, Heat
Treated, 150 ksi Minimum Tensile Strength
Type 1 Medium carbon, carbon boron, or medium carbon alloy steel.
Type 2 Withdrawn in November 1991.
A 563 Specification for Carbon and Alloy Steel Nuts
Type 3 Weathering steel. A 751 Test Methods, Practices, and Terminology for
NOTE 1—Bolts for general applications, including anchor bolts, are
Chemical Analysis of Steel Products
covered by Specification A 449. Also refer to Specification A 449 for B 695 Specification for Coatings of Zinc Mechanically
quenched and tempered steel bolts and studs with diameters greater than Deposited on Iron and Steel
11⁄2 in. but with similar mechanical properties. D 3951 Practice for Commercial Packaging
NOTE 2—A complete metric companion to Specification A 325 has F 436 Specification for Hardened Steel Washers
been developed—Specification A 325M; therefore, no metric equivalents F 606 Test Methods for Determining the Mechanical Prop-
are presented in this specification.
erties of Externally and Internally Threaded Fasteners,
1.4 This specification is applicable to heavy hex structural Washers, and Rivets
bolts only. For bolts of other configurations and thread lengths F 788/F 788M Specification for Surface Discontinuities of
with similar mechanical properties, see Specification A 449. Bolts, Screws, and Studs, Inch and Metric Series
1.5 Terms used in this specification are defined in Specifi- F 959 Specification for Compressible-Washer-Type Direct
cation F 1789. Tension Indicators for Use with Structural Fasteners
1.6 The following safety hazards caveat pertains only to F 1470 Guide for Fastener Sampling for Specified Mechani-
the test methods portion, Section 10, of this specification: This cal Properties and Performance Inspection
F 1789 Terminology for F16 Mechanical Fasteners
1
G 101 Guide for Estimating the Atmospheric Corrosion
This specification is under the jurisdiction of ASTM Committee F16 on
Fasteners and is the direct responsibility of Subcommittee F16.02 on Steel Bolts,
Resistance of Low-Alloy Steels
Nuts, Rivets, and Washers.
Current edition approved Jan. 1, 2004. Published January 2004. Originally
approved in 1964. Last previous edition approved in 2002 as A 325 – 02. 4
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
2
For ASME Boiler and Pressure Vessel Code applications see related Specifi- contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
cation SA-325 in Section II of that Code. Standards volume information, refer to the standard’s Document Summary page on
3
Published by American Institute of Steel Construction,One East Wacker Dr., the ASTM website.
Ste. 3100, Chicago, IL 60601-2001.

*A Summary of Changes section appears at the end of this standard.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

1
 A 325 – 04
2.2 ASME Standards:5 3.2.3 When Specification A 194/A 194M Gr. 2H zinc-
B 1.1 Unified Screw Threads coated nuts are supplied, the zinc coating, overtapping, lubri-
B 18.2.6 Fasteners for Use in Structural Applications cation, and rotational capacity testing shall be in accordance
B 18.24.1 Part Identifying Number (PIN) Code System with Specification A 563.
2.3 Military Standard:6 3.3 Recommended Washers:
MIL-STD-105 Sampling Procedure and Tables for Inspec- 3.3.1 Washers conforming to Specification F 436 are the
tion by Attributes recommended washers for use with Specification A 325 heavy
hex structural bolts. The washers shall have a surface finish for
3. Ordering Information
each type of bolt as follows:
3.1 Orders for heavy hex structural bolts under this speci- Bolt Type and Finish Washer Finish
fication shall include the following:
3.1.1 Quantity (number of pieces of bolts and accessories).
1, plain (uncoated) plain (uncoated)
3.1.2 Size, including nominal bolt diameter, thread pitch, 1, zinc coated zinc coated
and bolt length. 3, plain weathering steel, plain
3.1.3 Name of product, heavy hex structural bolts.
3.4 Other Accessories:
3.1.4 When bolts threaded full length are required, Supple-
mentary Requirement S1 shall be specified. 3.4.1 When compressible washer type direct tension indica-
3.1.5 Type of bolt: Type 1 or 3. When type is not specified, tors are specified to be used with these bolts, they shall
either Type 1 or Type 3 shall be furnished at the supplier’s conform to Specification F 959 Type 325.
option.
3.1.6 ASTM designation and year of issue. 4. Materials and Manufacture
3.1.7 Other components such as nuts, washers, and com- 4.1 Heat Treatment:
pressible washer-type direct-tension indicators, if required. 4.1.1 Type 1 bolts produced from medium carbon steel shall
3.1.7.1 When such other components are specified to be be quenched in a liquid medium from the austenitizing
furnished, also state “Nuts, washers, and direct tension indica- temperature. Type 1 bolts produced from medium carbon steel
tors, or combination thereof, shall be furnished by lot number.” to which chromium, nickel, molybdenum, or born were inten-
3.1.8 Zinc Coating—Specify the zinc coating process re- tionally added shall be quenched only in oil from the austen-
quired, for example, hot dip, mechanically deposited, or no itizing temperature.
preference (see 4.3). 4.1.2 Type 3 bolts shall be quenched only in oil from the
3.1.9 Other Finishes—Specify other protective finish, if austenitizing temperature.
required. 4.1.3 Type 1 bolts, regardless of the steel used, and Type 3
3.1.10 Test reports, if required (see Section 13). bolts shall be tempered by reheating to not less than 800°F.
3.1.11 Supplementary or special requirements, if required. 4.2 Threading—Threads shall be cut or rolled.
3.1.12 For establishment of a part identifying system, see
4.3 Zinc Coatings, Hot-Dip and Mechanically Deposited:
ASME B18.24.1.
4.3.1 When zinc-coated fasteners are required, the pur-
NOTE 3—A typical ordering description follows: 1000 pieces 11⁄8-7 chaser shall specify the zinc coating process, for example, hot
UNC in. dia 3 4 in. long heavy hex structural bolt, Type 1 ASTM dip, mechanically deposited, or no preference.
A 325–02, each with one hardened washer, ASTM F 436 Type 1, and one
heavy hex nut, ASTM A 563 Grade DH. Each component hot-dip
4.3.2 When hot-dip is specified, the fasteners shall be
zinc-coated. Nuts lubricated. zinc-coated by the hot-dip process and the coating shall
conform to the coating weight/thickness and performance
3.2 Recommended Nuts: requirements of Class C of Specification A 153.
3.2.1 Nuts conforming to the requirements of Specification
4.3.3 When mechanically deposited is specified, the fasten-
A 563 are the recommended nuts for use with Specification
ers shall be zinc-coated by the mechanical deposition process
A 325 heavy hex structural bolts. The nuts shall be of the class
and the coating shall conform to the coating weight/thickness
and have a surface finish for each type of bolt as follows:
and performance requirements of Class 50 of Specification
Bolt Type and Finish Nut Class and Finish
B 695.
4.3.4 When no preference is specified, the supplier shall
1, plain (noncoated) A 563-C, C 3, D, DH, DH3, furnish either a hot-dip zinc coating in accordance with
plain
1, zinc coated A 563-DH, zinc coated Specification A 153, Class C, or a mechanically deposited zinc
3, plain A 563-C3, DH3, plain coating in accordance with Specification B 695, Class 50.
3.2.2 Alternatively, nuts conforming to Specification A 194/ Threaded components (bolts and nuts) shall be coated by the
A 194M Gr. 2H are considered a suitable substitute for use same zinc-coating process and the supplier’s option is limited
with Specification A 325 Type 1 heavy hex structural bolts. to one process per item with no mixed processes in a lot.
4.4 Lubrication—When zinc-coated nuts are ordered with
the bolts, the nuts shall be lubricated in accordance with
5
Available from ASME International, Information Central, 22 Law Dr., PO Box Specification A 563, Supplementary Requirement S1, to mini-
2300, Fairfield, NJ 07007-2300
6
Available from USA Information Systems, Inc., 1092 Laskin Rd., Ste. 208, mize galling.
Virginia Beach, VA 23451. 4.5 Secondary Processing:

2
 A 325 – 04
4.5.1 If any processing, which can affect the mechanical TABLE 1 Chemical Requirements for Type 1 Bolts
properties or performance of the bolts, is performed after the
initial testing, the bolts shall be retested for all specified Carbon Steel
Element
mechanical properties and performance requirements affected Heat Product
Analysis Analysis
by the reprocessing.
4.5.2 When the secondary process is heat treatment, the Carbon 0.30–0.52 0.28–0.55
Manganese, min 0.60 0.57
bolts shall be tested for all specified mechanical properties. Hot Phosphorus, max 0.040 0.048
dip zinc-coated bolts shall be tested for all specified mechani- Sulfur, max 0.050 0.058
Silicon 0.15–0.30 0.13–0.32
cal properties and rotational capacity. If zinc-coated nuts are
relubricated after the initial rotational capacity tests, the
assemblies shall be retested for rotational capacity. Carbon Boron Steel
Element
5. Chemical Composition Heat Product
Analysis Analysis
5.1 Type 1 bolts shall be plain carbon steel, carbon boron Carbon 0.30–0.52 0.28–0.55
steel, alloy steel or alloy boron steel at the manufacturer’s Manganese, min 0.60 0.57
option, conforming to the chemical composition specified in Phosphorus, max 0.040 0.048
Sulfur, max 0.050 0.058
Table 1. Silicon 0.10–0.30 0.08–0.32
5.2 Type 3 bolts shall be weathering steel and shall conform Boron 0.0005–0.003 0.0005–0.003
to one of the chemical compositions specified in Table 2. The
selection of the chemical composition, A, B, C, D, E, or F, shall
be at the option of the bolt manufacturer. See Guide G 101 for Alloy Steel
Element
methods of estimating the atmospheric corrosion resistance of Heat Product
Analysis Analysis
low alloy steels.
Carbon 0.30–0.52 0.28–0.55
5.3 Product analyses made on finished bolts representing Manganese, min 0.60 0.57
each lot shall conform to the product analysis requirements Phosphorus, max 0.035 0.040
specified in Table 1 and Table 2, as applicable. Sulfur, max 0.040 0.045
Silicon 0.15–0.35 0.13–0.37
5.4 Heats of steel to which bismuth, selenium, tellurium, or Alloying Elements A A

lead has been intentionally added shall not be permitted for

Alloy Boron Steel
bolts.
Heat Product
5.5 Compliance with 5.4 shall be based on certification that Analysis Analysis
heats of steel having any of the listed elements intentionally
Carbon 0.30–0.52 0.28–0.55
added were not used to produce the bolts. Manganese, min 0.60 0.57
5.6 Chemical analyses shall be performed in accordance Phosphorus, max 0.035 0.040
with Test Methods, Practices, and Terminology A 751. Sulfur, max 0.040 0.045
Silicon 0.15–0.35 0.13–0.37
Boron 0.0005–0.003 0.0005–0.003
6. Mechanical Properties Alloying Elements A A

6.1 Hardness—The bolts shall conform to the hardness A

Steel, as defined by the American Iron and Steel Institute, shall be considered
specified in Table 3. to be alloy when the maximum of the range given for the content of alloying
elements exceeds one or more of the following limits: Manganese, 1.65 %; silicon,
6.2 Tensile Properties: 0.60 %; copper, 0.60 % or in which a definite range or a definite minimum quantity
6.2.1 Except as permitted in 6.2.2 for long bolts and 6.2.3 of any of the following elements is specified or required within the limits of the
for short bolts, sizes 1.00 in. and smaller having a length of 21⁄4 recognized field of constructional alloy steels: aluminum, chromium up to 3.99 %,
cobalt, columbium, molybdenum, nickel, titanium, tungsten, vanadium, zirconium,
D and longer, and sizes larger than 1.00 in. having a length of or any other alloying elements added to obtain a desired alloying effect.
3D and longer, shall be wedge tested full size and shall
conform to the minimum wedge tensile load and proof load or
alternative proof load specified in Table 4. The load achieved 6.2.4 For bolts on which both hardness and tension tests are
during proof load testing shall be equal to or greater than the performed, acceptance based on tensile requirements shall take
specified proof load. precedence in the event of low hardness readings.
6.2.2 When the length of the bolt makes full-size testing 6.3 Rotational Capacity Test:
impractical, machined specimens shall be tested and shall 6.3.1 Definition—The rotational capacity test is intended to
conform to the requirements specified in Table 5. When bolts evaluate the presence of a lubricant, the efficiency of the
are tested by both full-size and machined specimen methods, lubricant, and the compatibility of assemblies as represented by
the full-size test shall take precedence. the components selected for testing.
6.2.3 Sizes 1.00 in. and smaller having a length shorter than 6.3.2 Requirement—Zinc-coated bolts, zinc-coated wash-
21⁄4 D down to 2D, inclusive, that cannot be wedge tensile ers, and zinc-coated and lubricated nuts tested full size in an
tested shall be axially tension tested full size and shall conform assembled joint or tension measuring device, in accordance
to the minimum tensile load and proof load or alternate proof with 10.2, shall not show signs of failure when subjected to the
load specified in Table 4. Sizes 1.00 in. and smaller having a nut rotation in Table 6. The test shall be performed by the
length shorter than 2D that cannot be axially tensile tested shall responsible party (see Section 14) prior to shipment after zinc
be qualified on the basis of hardness. coating and lubrication of nuts (see 10.2 and Note 5).

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 A 325 – 04
TABLE 2 Chemical Requirements for Type 3 Heavy Hex Structural BoltsA
Composition, %
Type 3 BoltsA
Element A B C D E F
Carbon:
Heat analysis 0.33–0.40 0.38–0.48 0.15–0.25 0.15–0.25 0.20–0.25 0.20–0.25
Product analysis 0.31–0.42 0.36–0.50 0.14–0.26 0.14–0.26 0.18–0.27 0.19–0.26

Manganese:
Heat analysis 0.90–1.20 0.70–0.90 0.80–1.35 0.40–1.20 0.60–1.00 0.90–1.20
Product analysis 0.86–1.24 0.67–0.93 0.76–1.39 0.36–1.24 0.56–1.04 0.86–1.24

Phosphorus:
Heat analysis 0.035 max 0.06–0.12 0.035 max 0.035 max 0.035 max 0.035 max
Product analysis 0.040 max 0.06–0.125 0.040 max 0.040 max 0.040 max 0.040 max

Sulfur:
Heat analysis 0.040 max 0.040 max 0.040 max 0.040 max 0.040 max 0.040 max
Product analysis 0.045 max 0.045 max 0.045 max 0.045 max 0.045 max 0.045 max

Silicon:
Heat analysis 0.15–0.35 0.30–0.50 0.15–0.35 0.25–0.50 0.15–0.35 0.15–0.35
Product analysis 0.13–0.37 0.25–0.55 0.13–0.37 0.20–0.55 0.13–0.37 0.13–0.37

Copper:
Heat analysis 0.25–0.45 0.20–0.40 0.20–0.50 0.30–0.50 0.30–0.60 0.20–0.40
Product analysis 0.22–0.48 0.17–0.43 0.17–0.53 0.27–0.53 0.27–0.63 0.17–0.43

Nickel:
Heat analysis 0.25–0.45 0.50–0.80 0.25–0.50 0.50–0.80 0.30–0.60 0.20–0.40
Product analysis 0.22–0.48 0.47–0.83 0.22–0.53 0.47–0.83 0.27–0.63 0.17–0.43

Chromium:
Heat analysis 0.45–0.65 0.50–0.75 0.30–0.50 0.50–1.00 0.60–0.90 0.45–0.65
Product analysis 0.42–0.68 0.47–0.83 0.27–0.53 0.45–1.05 0.55–0.95 0.42–0.68

Vanadium:
B B B B B
Heat analysis 0.020 min
B B B B B
Product analysis 0.010 min

Molybdenum:
B B B B
Heat analysis 0.06 max 0.10 max
B B B B
Product analysis 0.07 max 0.11 max

Titanium:
B B B B B
Heat analysis 0.05 max
B B B B B
Product analysis 0.06 max
A
A, B, C, D, E, and F are classes of material used for Type 3 bolts. Selection of a class shall be at the option of the bolt manufacturer.
B
These elements are not specified or required.

TABLE 3 Hardness Requirements for Bolts 6.3.3.2 Inability to remove the nut after installing to the
Bolt Length,
Brinell Rockwell C rotation specified in Table 6.
Bolt Size, in. in. Min Max Min Max 6.3.3.3 Shear failure of the threads as determined by visual
⁄
12 to 1, incl Less than 253 319 25 34 examination of bolt and nut threads following removal.
2D A
2D and ... 319 ... 34
6.3.3.4 Torsional or torsional/tension failure of the bolt.
over Elongation of the bolt, in the threads between the nut and bolt
11⁄8 to 11⁄2 , Less than 223 286 19 30 head, is to be expected at the required rotation and is not to be
incl 3D A
3D and ... 286 ... 30 classified as a failure.
over
A
Sizes 1.00 in. and smaller having a length shorter than 2D and sizes larger 7. Dimensions
than 1.00 in. having a length shorter than 3D are subject only to minimum and
maximum hardness. 7.1 Head and Body:
D = Nominal diameter or thread size. 7.1.1 The bolts shall conform to the dimensions for heavy
hex structural bolts specified in ANSI/ASME B18.2.6.
6.3.3 Acceptance Criterion—The bolt and nut assembly 7.1.2 The thread length shall not be changed except as
shall be considered as non-conforming if the assembly fails to provided in Supplementary Requirement S1. Bolts with thread
pass any one of the following specified requirements: lengths other than those required by this specification shall be
6.3.3.1 Inability to install the assembly to the nut rotation in ordered under Specification A 449.
Table 6. 7.2 Threads:

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 A 325 – 04
TABLE 4 Tensile Load Requirements for Full-Size Bolts 7.2.3 The gaging limit for bolts shall be verified during
Proof Load,B Alternative manufacture. In case of dispute, a calibrated thread ring gage of
Length Proof the same size as the oversize limit in 7.2.2 (Class X tolerance,
Bolt Size, Threads per Measure- Load,B Yield
Inch, and Series Stress Area,A Tensile Load,B ment Strength gage tolerance plus) shall be used to verify compliance. The
Designation in.2 min, lbf Method Method gage shall assemble with hand effort following application of
Column 1 Column 2 Column 3 Column 4 Column 5 light machine oil to prevent galling and damage to the gage.
⁄
12 –13 UNC 0.142 17 050 12 050 13 050 These inspections, when performed to resolve controversy,
5⁄8 –11 UNC 0.226 27 100 19 200 20 800 shall be conducted at the frequency specified in the quality
3⁄4 –10 UNC 0.334 40 100 28 400 30 700
7⁄8 –9 UNC 0.462 55 450 39 250 42 500
assurance provisions of ASME B18.2.6.

1–8 UNC 0.606 72 700 51 500 55 750 8. Workmanship

11⁄8 –7 UNC 0.763 80 100 56 450 61 800
11⁄8 –8 UN 0.790 82 950 58 450 64 000 8.1 The allowable limits, inspection, and evaluation of the
11⁄4 –7 UNC 0.969 101 700 71 700 78 500 surface discontinuities, quench cracks, forging cracks, head
11⁄4 –8 UN 1.000 105 000 74 000 81 000
bursts, shear bursts, seams, folds, thread laps, voids, tool
13⁄8 –6 UNC 1.155 121 300 85 450 93 550 marks, nicks, and gouges shall be in accordance with Specifi-
13⁄8 –8 UN 1.233 129 500 91 250 99 870 cation F 788/F 788M (See Note 4).
11⁄2 –6 UNC 1.405 147 500 104 000 113 800
11⁄2 –8 UN 1.492 156 700 110 400 120 850 NOTE 4—Specification F 788/F 788M nor F 1470 guarantee 100%
A
The stress area is calculated as follows: freedom from head bursts. Sampling is designed to provide a 95%
confidence level of freedom from head bursts in any test lot. Head bursts,
As 5 0.7854 [D 2 ~0.9743/n!#2 within the limits in Specification F 788/F 788M, are unsightly but do not
affect mechanical properties or functional requirements of the bolt.
where:
As = stress area, in.2,
D = nominal bolt size, and 9. Number of Tests and Retests
n = threads per inch.
9.1 Testing Responsibility:
9.1.1 Each lot shall be tested by the manufacturer prior to
B
Loads tabulated are based on the following: shipment in accordance with the lot identification control
Bolt Size, in. Column 3 Column 4 Column 5 quality assurance plan in 9.2 through 9.5.
⁄ to 1, incl
12 120 000 psi 85 000 psi 92 000 psi 9.1.2 When bolts are furnished by a source other than the
11⁄8 to 11⁄2 , incl 105 000 psi 74 000 psi 81 000 psi manufacturer, the Responsible Party as defined in 14 shall be
responsible for assuring all tests have been performed and the
bolts comply with the requirements of this specification (see
7.2.1 Uncoated—Threads shall be the Unified Coarse 4.5).
Thread Series as specified in ANSI/ASME B1.1, and shall have 9.2 Purpose of Lot Inspection—The purpose of a lot inspec-
Class 2A tolerances. tion program is to ensure that each lot conforms to the
7.2.2 Coated—Unless otherwise specified, zinc-coated bolts requirements of this specification. For such a plan to be fully
to be used with zinc-coated nuts or tapped holes that are tapped effective it is essential that secondary processors, distributors,
oversize, in accordance with Specification A 563, shall have and purchasers maintain the identification and integrity of each
Class 2A threads before hot-dip or mechanically deposited zinc lot until the product is installed.
coating. After zinc coating, the maximum limits of pitch and 9.3 Lot Method—All bolts shall be processed in accordance
major diameter shall not exceed the Class 2A limit by more with a lot identification-control quality assurance plan. The
than the following amounts: manufacturer, secondary processors, and distributors shall
identify and maintain the integrity of each production lot of
bolts from raw-material selection through all processing op-
Oversize Limit, in.A
erations and treatments to final packing and shipment. Each lot
Nominal Bolt
Hot-Dip Mechanical shall be assigned its own lot-identification number, each lot
Zinc Zinc shall be tested, and the inspection test reports for each lot shall
Diameter (in.)
be retained.
1⁄2 0.018 0.012 9.4 Lot Definition—A lot shall be a quantity of uniquely
⁄
9 16 , 5⁄8 , 3⁄4 0.020 0.013 identified heavy hex structural bolts of the same nominal size
7⁄8 0.022 0.015
1 to 11⁄4 0.024 0.016 and length produced consecutively at the initial operation from
13⁄8 , 11⁄2 0.027 0.018 a single mill heat of material and processed at one time, by the
same process, in the same manner so that statistical sampling is
A
Hot-dip zinc nuts are tapped oversize after coating, and mechanical zinc- valid. The identity of the lot and lot integrity shall be
coated nuts are tapped oversize before coating.
maintained throughout all subsequent operations and packag-
ing.

5
 A 325 – 04
TABLE 5 Tensile Strength Requirements for Specimens Machined from Bolts
Bolt Diameter, in. Tensile Strength, min, psi (MPa) Yield Strength, min, psi (MPa) Elongation, in 4D, min, % Reduction of Area, min, %
⁄ to 1, incl.
12 120 000 (825) 92 000 (635) 14 35
Over 1 to 11⁄2 105 000 (725) 81 000 (560) 1435

TABLE 6 Rotational Capacity Test for Zinc-Coated Bolts specified proof load. After initial tightening, the nut position
Nominal Nut Rotation, degrees shall be marked relative to the bolt, and the rotation shown in
Bolt Length, in. (turn) Table 6 shall be applied. During rotation, the bolt head shall be
Up to and including 4 3 dia 240 (2⁄3) restrained from turning.
Over 4 3 dia, but not 360 (1)
exceeding 8 3 dia NOTE 5—Rotational capacity tests shall apply only to matched assem-
Over 8 3 dia, but not 420 (11⁄6) bly lots that contain on A 325 bolt, one A 563 lubricated nut, and one
exceeding 12 3 dia
Over 12 3 dia. Test not applicable
F 436 washer that have been zinc coated in accordance with either
Specifications A 153 or B 695. Both the bolt and nut components of the
matched assembly shall be zinc coated using the same process.

9.5 Number of Tests—The minimum number of tests from 11. Inspection

each lot for the tests specified below shall be as follows: 11.1 If the inspection described in 11.2 is required by the
Tests Number of Tests purchaser, it shall be specified in the inquiry and contract or
in Accordance With
order.
11.2 The purchaser’s representative shall have free entry to
Hardness, tensile all parts of the manufacturer’s works, or supplier’s place of
strength, proof load, Guide F 1470
and rotational capacity business, that concern the manufacture or supply of the
material ordered. The manufacturer or supplier shall afford the
Coating weight/ The referenced coating purchaser’s representative all reasonable facilities to satisfy
thickness specificationA
him that the material is being furnished in accordance with this
Surface discontinuities Specification F 788/ specification. All tests and inspections required by the specifi-
F 788M cation that are requested by the purchaser’s representative shall
Dimensions and ASME B18.2.6 be made before shipment, and shall be conducted as not to
thread fit interfere unnecessarily with the operation of the manufactur-
A
Guide F 1470 applies if the coating specification does not specify a testing er’s works or supplier’s place of business.
frequency.
12. Rejection and Rehearing
10. Test Methods
12.1 Disposition of nonconforming bolts shall be in accor-
10.1 Tensile, Proof Load, and Hardness: dance with the Guide F 1470 section titled “Disposition of
10.1.1 Tensile, proof load, and hardness tests shall be Nonconforming Lots.”
conducted in accordance with Test Methods F 606.
10.1.2 Tensile strength shall be determined using the Wedge 13. Certification
or Axial Tension Testing Method of Full Size Product Method
or the Machined Test Specimens Method depending on size 13.1 When specified on the purchase order, the manufac-
and length as specified in 6.2.1-6.2.4. Fracture on full-size tests turer or supplier, whichever is the responsible party as defined
shall be in the body or threads of the bolt without a fracture at in Section 14, shall furnish the purchaser a test reports that
the junction of the head and body. includes the following:
10.1.3 Proof load shall be determined using Method 1, 13.1.1 Heat analysis, heat number, and a statement certify-
Length Measurement, or Method 2, Yield Strength, at the ing that heats having the elements listed in 5.4 intentionally
option of the manufacturer. added were not used to produce the bolts,
10.2 Rotational Capacity—The zinc-coated bolt shall be 13.1.2 Results of hardness, tensile, and proof load tests,
placed in a steel joint or tension measuring device and 13.1.3 Results of rotational capacity tests. This shall include
assembled with a zinc-coated washer and a zinc-coated and the test method used (solid plate or tension measuring device);
lubricated nut with which the bolt is intended to be used (see and the statement “Nuts lubricated” for zinc-coated nuts when
Note 5). The nut shall have been provided with the lubricant shipped with zinc-coated bolts,
described in the last paragraph of the Manufacturing Processes 13.1.4 Zinc coating measured coating weight/thickness for
section of Specification A 563. The joint shall be one or more coated bolts,
flat structural steel plates or fixture stack up with a total 13.1.5 Statement of compliance of visual inspection for
thickness, including the washer, such that 3 to 5 full threads of surface discontinuities (Section 8),
the bolt are located between the bearing surfaces of the bolt 13.1.6 Statement of compliance with dimensional and
head and nut. The hole in the joint shall have the same nominal thread fit requirements,
diameter as the hole in the washer. The initial tightening of the 13.1.7 Lot number and purchase order number,
nut shall produce a load in the bolt not less than 10 % of the 13.1.8 Complete mailing address of responsible party, and

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 A 325 – 04
13.1.9 Title and signature of the individual assigned certi- 15.5 Type and manufacturer’s or private label distributor’s
fication responsibility by the company officers. identification shall be separate and distinct. The two identifi-
13.2 Failure to include all the required information on the cations shall preferably be in different locations and, when on
test report shall be cause for rejection. the same level, shall be separated by at least two spaces.
16. Packaging and Package Marking
14. Responsibility
16.1 Packaging:
14.1 The party responsible for the fastener shall be the 16.1.1 Unless otherwise specified, packaging shall be in
organization that supplies the fastener to the purchaser and accordance with Practice D 3951.
certifies that the fastener was manufactured, sampled, tested 16.1.2 When zinc coated nuts are included on the same
and inspected in accordance with this specification and meets order as zinc coated bolts, the bolts and nuts shall be shipped
all of its requirements. in the same container.
16.1.3 When special packaging requirements are required,
15. Product Marking they shall be defined at the time of the inquiry and order.
15.1 Manufacturer’s Identification— All Type 1 and 3 bolts 16.2 Package Marking:
shall be marked by the manufacturer with a unique identifier to 16.2.1 Each shipping unit shall include or be plainly marked
identify the manufacturer or private label distributor, as appro- with the following information:
priate. 16.2.1.1 ASTM designation and type,
15.2 Grade Identification: 16.2.1.2 Size,
15.2.1 Type 1 bolts shall be marked “A 325.” 16.2.1.3 Name and brand or trademark of the manufacturer,
16.2.1.4 Number of pieces,
15.2.2 Type 3 bolts shall be marked “A 325” with the
16.2.1.5 Lot number; when nuts, washers or direct tension
“A 325” underlined. The use of additional distinguishing
indicators, or combination thereof, are ordered with A 325
marks to indicate that the bolts are weathering steel shall be at
heavy hex structural bolts, the shipping unit shall be marked
the manufacturer’s option.
with the lot number in addition to the marking required by the
15.3 Marking Location and Methods—All marking shall be applicable product specification,
located on the top of the bolt head and shall be either raised or 16.2.1.6 Purchase order number, and
depressed at the manufacturer’s option. 16.2.1.7 Country of origin.
15.4 Acceptance Criteria—Bolts which are not marked in
accordance with these provisions shall be considered noncon- 17. Keywords
forming and subject to rejection. 17.1 bolts; carbon steel; steel; structural; weathering steel

SUPPLEMENTARY REQUIREMENTS

The following supplementary requirements shall apply only when specified by the purchaser in the
contract or order. Details of these supplementary requirements shall be agreed upon in writing between
the manufacturer and purchaser. Supplementary requirements shall in no way negate any requirement
of the specification itself.

S1. Bolts Threaded Full Length hand as far as the thread will permit, shall not exceed the length
S1.1 Bolts with nominal lengths equal to or shorter than of 21⁄2 threads for bolt sizes 1 in. and smaller, and 31⁄2 threads
four times the nominal bolt diameter shall be threaded full for bolt sizes larger than 1 in.
length. Bolts need not have a shoulder, and the distance from S1.2 Bolts shall be marked in accordance with Section 15,
the underhead bearing surface to the first complete (full form) except that the symbol shall be “A 325 T” instead of “A 325.”
thread, as measured with a GO thread ring gage, assembled by

7
 A 325 – 04
SUMMARY OF CHANGES

Committee F16 has identified the location of selected changes to this standard since the last issue, A 325–02,
that may impact the use of this standard. (Approved Jan. 1, 2004.)

(1) Revised Certification Section 13.1.5 to require statement of

compliance of visual inspection for all surface discontinuities.

Committee F16 has identified the location of selected changes to this standard since the last issue, A 325–01, that may impact
the use of this standard. (Approved Jan. 10, 2002.)

(1) In 1.4 limited specification to heavy hex structural bolts (11) In 7.1.1 changed the dimensional reference from B18.2.1
only. to B18.2.6.
(2) In 4.1 revised to require that Type 3 bolts be quenched in (12) 7.2.2 revised to specify maximum pitch and major
oil. diameter limits for mechanically coated bolts.
(3) In 4.5.1 revised to require retesting only for properties (13) Deleted Table 7 (formerly Table 6), “Sample Size for
affected by the secondary processing. Inspection of Hot-Dip or Mechanically Deposited Zinc-Coated
(4) In 4.5.2 rephrased to preclude the implication that black Threads” and referenced ASME B18.2.6, which includes
bolts require rotational capacity testing. references for testing frequency.
(5) In Table 2, reduced the phosphorus limits for compositions (14) Deleted former section 9, “Head Bursts,” and included
A, D, E, and F and the sulfur limits for compositions A, B, and the requirements by reference to Specification F 788/F 788M
D. in 8.1.
(6) In 6.2.1 revised the minimum length for full-size wedge (15) In 9.3 and 9.4 changed “Production Lot” to “Lot” and
testing. redefined “Lot.”
(7) In 6.2.3 provided for full-size axially tension testing bolts (16) 9.5, “Number of Tests,” revised to invoke Specification
shorter than 21⁄4 D down to 2D. Also added requirements for F 1470 for hardness, tensile, proof load, and rotational capacity
qualifying short bolts on the basis of hardness. tests. Coating weight/thickness and surface discontinuities
(8) In Table 3, Hardness, changed 3D to 2D for sizes 1.00 in. sampling referenced to the applicable spec. Dimensional and
and smaller thread compliance sampling referenced to ASME B18.2.6.
(9) Added Table 5 specifying tensile, elongation, and reduc- (17) Section 12, “Rejection and Rehearing,” revised to invoke
tion in area requirements for machined specimens. F 1470.
(10) In 7.1.1 deleted all wording that permitted the purchaser (18) In 15.2.1 deleted option permitting marking with three
to specify dimensions other than “heavy hex structural.” radial lines 120° apart.

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