ASTM A325M Specification

ASTM A325M - Standard Specification for Structural Bolts, Steel, Heat Treated 830 MPa Minimum Tensile Strength

This specification covers two types of quenched and tempered steel heavy hex bolts in metric and imperial sizes for structural purpose. Metric size bolts are produced from M12 to M36 as per ASTM A325M & imperial size bolts are produced from 1/2" to 1-1/2" as per ASTM A325. These boltings are intended for used in structural connections. FerroBend manufactures and supplies ASTM A325 Type 1 & Type 3 heavy hex bolts with EN 10204 Type 3.1 Certification.

ASTM A325M Grades

Grade Class
Type 1 Carbon Steel, Carbon Boron Steel, Alloy Steel or Alloy Boron Steel
Type 2 Withdrawn
Type 3 A B C D E F

ASTM A325M Chemical Composition

Element Type 1 % Type 3 %
Carbon Steel Carbon Boron Steel Alloy Steel Alloy Boron Steel A B C D E F
Carbon 0.28 - 0.55 0.28 - 0.55 0.28 - 0.55 0.28 - 0.55 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 0.57 min 0.57 min 0.57 min 0.57 min 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 0.048 max 0.048 max 0.040 max 0.040 max 0.040 max 0.040 max 0.040 max 0.040 max 0.040 max 0.040 max
Sulfur 0.058 max 0.058 max 0.045 max 0.045 max 0.045 max 0.045 max 0.045 max 0.045 max 0.045 max 0.045 max
Silicon 0.13 - 0.32 0.08 - 0.32 0.13 - 0.37 0.13 - 0.37 0.13 - 0.37 0.25 - 0.55 0.13 - 0.37 0.20 - 0.55 0.13 - 0.37 0.13 - 0.37
Boron -- 0.0005 - 0.003 -- 0.0005 - 0.003 -- -- -- -- -- --
Copper -- -- -- -- 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 -- -- -- -- 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 -- -- -- -- 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 -- -- -- -- -- -- 0.010 min -- -- --
Molybdenum -- -- -- -- -- 0.07 max -- 0.11 max -- --
Titanium -- -- -- -- -- -- -- 0.06 max -- --

ASTM A325M Mechanical Properties

Nominal Diameter, mm Tensile Strength, min, Mpa Yield Strength, min, Mpa Elongation in 4D, min, % Reduction in Area, min, %
M12 to M36, Inclusive 830 660 14 35

Hardness Requirements for ASTM A325M Bolts

Bolt Size, mm Bolt Length, mm Brinell Rockwell C
Min Max Min Max
M12 to M24, inclusive Less than 2D
2D and over
253
--
319
319
25
--
34
34
M25 to M36, Inclusive Less than 3D
3D and over
253
--
319
319
25
--
34
34

Recommended Nuts & Washers

Bolt Type and Finish Nut Class & Finish Specification Washer Finish
Plain (Non Coated) ASTM F563/F563M Grade 8S or 8S3, Plain (Non Coated) ASTM F436/F436M, Plain (Non Coated)
Zinc Coated ASTM F563/F563M Grade 10S, Zinc Coated ASTM F436/F436M, Zinc Coated
Coated in accordance with ASTM F1136M, Grade 3 ASTM F563/F563M Grade 10S, Coated in accordance with ASTM F1136 ASTM F436/F436M, Coated in accordance with ASTM F1136
Plain ASTM F563/F563M Grade 8S3, Plain ASTM F436/F436M, Plain

ASTM A325M Bolt Marking

Grade Marking Details
Type 1 Type 1 bolts shall me marked "A325M" and "8S". In addition, bolts marked "8.8S" shall be an acceptable marking
provided they also meet the requirements of ISO 7412.
Type 3 Type 1 bolts shall me marked "A325M" and "8S3". In addition, bolts marked "8.8S" shall be an acceptable marking
provided they also meet the requirements of ISO 7412. The use of additional distinguishing marks to indicate
the bolts are weathering steel shall be the manufacturer's discretion.