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ASTM A325 Specification

ASTM A325 - 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 A325 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Type 2 Withdrawn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 A325 Properties

ASTM A325 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 A325 Mechanical Requirement

Nominal Diameter, mm Tensile Strength, min, ksi Yield Strength, min, ksi Elongation in 4D, min, % Reduction in Area, min, %
1/2" to 1", Inclusive 120 92 14 35
Over 1 to 1-1/2" 105 81 14 35

Hardness Requirements for ASTM A325 Bolts

Bolt Size, Inch Bolt Length, Inch Brinell Rockwell C
Min Max Min Max
1/2" to 1", inclusive Less than 2D
2D and over
253
--
319
319
25
--
34
34
1-1/8" to 1-1/2", inclusive Less than 3D
3D and over
223
--
286
286
19
--
30
30

where D is nominal diameter or thread size

Recommended Nuts & Washers

Bolt Type and Finish Nut Class & Finish Specification Washer Finish
Plaing (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 A325 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.