Blog
  2. ASTM
  3. Structural Bolts
  4. ASTM A325/A325M Specification

ASTM A325/A325M Bolts Specification

Carbon Steel, Alloy Steel And Weatherng Steel Structural Bolts, Hex Cap Screws and Studs Heat Treated to 120/105 ksi Minimum Tensile Strength

Related Specifications of ASTM A325/A325M Bolting

A242/A242M A588/A588M A606/A606M A709/A709M F2482

ASTM A325/A325M Recommended Nuts

Bolt Type and Finish Nut Class and Finish
1, plain (noncoated) A563-C, C3, D, DH, DH3, plain
1, zinc coated A563-DH, zinc coated
1, coated in accordance with Specification F1136, Grade 3 A563-DH coated in accordance with Specification F1136, Grade 5
3, plain A563-C3, DH3, plain

ASTM A325/A325M Recommended Washers

Bolt Type and Finish Washer Finish
1, plain (uncoated) plain (uncoated)
1, zinc coated zinc coated
1, coated in accordance with Specification F1136, Grade 3 coated in accordance with Specification F1136, Grade 3
3, plain weathering steel, plain

ASTM A325/A325M Chemical Requirements

ASTM A325/A325M Chemical Requirements for Type 1 Bolts

Element C Mn, min P, max S, max Si B Alloying Elements
Carbon Steel Heat analysis 0.30-0.52 0.6 0.04 0.05 0.15-0.30 . . . . . .
Product analysis 0.28-0.55 0.57 0.048 0.058 0.13-0.32 . . . . . .
Carbon Boron Steel Heat analysis 0.30-0.52 0.6 0.04 0.05 0.10-0.30 0.0005-0.003 . . .
Product analysis 0.28-0.55 0.57 0.048 0.058 0.08-0.32 0.0005-0.003 . . .
Alloy Steel Heat analysis 0.30-0.52 0.6 0.04 0.05 0.15-0.35 . . . A
Product analysis 0.28-0.55 0.57 0.048 0.058 0.13-0.37 . . . A
Alloy Boron Steel Heat analysis 0.30-0.52 0.6 0.04 0.05 0.15-0.35 0.0005-0.003 A
Product analysis 0.28-0.55 0.57 0.048 0.058 0.13-0.37 0.0005-0.003 A

ASTM A325/A325M Chemical Requirements for Type 3 Heavy Hex Structural BoltsA

Element Composition, % Type 3 BoltsA
A B C D E F
C 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
Mn 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
P 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
S 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
Si 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
Cu 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
Ni 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
Cr 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
V Heat analysis B B 0.020 min B B B
Product analysis B B 0.010 min B B B
Mo Heat analysis B 0.06 max B 0.10 max B B
Product analysis B 0.07 max B 0.11 max B B
Ti Heat analysis B B B 0.05 max B B
Product analysis B B B 0.06 max B B

ASTM A325/A325M Mechanical Requirements

ASTM A325/A325M Hardness Requirements for Bolts

Size, in. Nominal Length, in. Brinell Rockwell C
min max min max
1⁄2 to 1, incl. Less than 2D 2D and longer 253 319 25 34
... 319 ... 34
Over 1 to 1 1⁄2, incl Less than 3D 3D and longer 223 286 19 30
... 286 ... 30

ASTM A325/A325M Tensile Load Requirements for Bolts Tested Full-Size

Bolt Size, Threads per Inch, and Series Designation Stress Area,A in.2 Tensile Load,B lbf min Proof Load,Length Measurement Method Alternative Proof Load,B lbf Yield Strength Method
1⁄2 -13 UNC 0.142 17 050 12 050 13 050
5⁄8-11 UNC 0.226 27 100 19 200 20 800
3⁄4-10 UNC 0.334 40 100 28 400 30 700
7⁄8-9 UNC 0.462 55 450 39 250 42 500
1-8 UNC 0.606 72 700 51 500 55 750
1 1⁄8-7 UNC 0.763 80 100 56 450 61 800
1 1⁄4-7 UNC 0.969 101 700 71 700 78 500
1 3⁄8-6 UNC 1.155 121 300 85 450 93 550
1 1⁄2-6 UNC 1.405 147 500 104 000 113 800
  • A The stress area is calculated as follows
    • As = 0.7854 [D - (0.9743/n)]2
  • where:
    • As = stress area, in.2
    • D = nominal bolt size, and
    • n = threads per inch.
  • B Loads tabulated are based on the following:
    • Bolt Size, in. Tensile Load,B lbf min Proof Load,Length Measurement Method Alternative Proof Load,B lbf Yield Strength Method
    1⁄2 to 1, incl 120 000 psi 85 000 psi 92 000 psi
    1 1⁄8 to 1 1⁄2, inc 105 000 psi 74 000 psi 81 000 psi

ASTM A325/A325M 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, %
1⁄2 to 1, incl. 120 000 (825) 92 000 (635) 14 35
Over 1 to 11⁄2 105 000 (725) 81 000 (560) 14

35

ASTM A325/A325M Rotational Capacity Test for Zinc-Coated Bolts

Up to and including 4 × dia 240 (2⁄3 )
Over 4 × dia, but not exceeding 8 × dia 360 (1)
Over 8 × dia, but not exceeding 12 × dia 420 (11⁄6)
Over 12 × dia. Test not applicable

ASTM A325/A325M Dimensions

Nominal Bolt Diameter (in.) Oversize Limit, in.A
Hot-Dip Zinc Mechanical Zinc
1⁄2 0.018 0.012
9⁄16 , 5⁄8, 3⁄4 0.02 0.013
7⁄8 0.022 0.015
1 to 1 1⁄4 0.024 0.016
1 3⁄8 , 1 1⁄2 0.027 0.018

ASTM A325/A325M Bolting Surface Treatment Specifications

ASTM A325/A325M Bolting Components Marking

Product Shall be Marked with our manufacturing trade mark "TorqBolt" or "TB" along with the designated Grade.
Grade and manufacturer’s identification symbols shall be applied to one end of studs and to the heads of bolts and screws of all sizes. (If the available area is inadequate, the grade symbol may be marked on one end and the manufacturer’s identification symbol marked on the other end.) For bolts and screws smaller than 1⁄4 in. [6 mm] in diameter and studs smaller than 3⁄8 in. [10 mm] in diameter and for 1⁄4 in. [6 mm] in diameter studs requiring more than a total of three symbols, the marking shall be a matter of agreement between the purchaser and the manufacturer.

ASME Dimensional Standards

ASTM A325/A325M Bolting Certifications

  • EN 10204 3.1
  • EN 10204 3.2
  • PED 2014/68/EC
  • MERKBLATT AD 2000 W2/W7/W10
  • API 20 E BSL 1/ BSL 2
  • NACE MR 0175
  • NACE MR 0103

ASTM A325/A325M Testing Standards

ASME Threading Specifications

ASTM A325/A325M Supplementary Requirements

S1. Bolts Threaded Full Length