ASTM A325 Specification for heat treated carbon & weathering steel bolts, steel with 120 ksi Minimum Tensile Strength, for use in structural bolting applications.

ASTM A325 specification covers two types of quenched and tempered steel heavy hex bolts in metric and imperial sizes for structural purpose. The specification includes type 1 & type 3 fastener material intended for structural bolting purpose. Type 1 is a heat treated high strength plain carbon, carbon-boron, alloy steel or alloy boron steel bolting materials with minimum tensile requirement of 105 ksi, yield 81 ksi and maximum hardness limit of 25 - 35 HRC. Type 3 is heat treated weathering steel bolting material with similar strength requirement to type 1 but greater corrosion protection and are prominently used in humid weather conditions.

Bolt Grades

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Type 2	Withdrawn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

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	...	...

Mechanical Properties

Nominal Diameter, Inch	Tensile Strength, min, ksi	Yield Strength, min, ksi	Elongation in 4D, min, %	Reduction in Area, min, %	Bolt Length, Inch	Brinell		Rockwell C
						Min	Max	Min	Max
						1/2" to 1", Inclusive	120	92	14	35	Less than 2D 2D and over	253 ...	319 319	25 ...	34 34
Over 1 to 1-1/2"	105	81	14	35	Less than 3D 3D and over	223 ...	286 286	19 ...	30 30

Recommended Nuts & Washers

Nuts			Washers
Type 1		Type 3	Type 1	Type 3
Plain	Galvanized	Plain
ASTM A563 Grade C, C3, D, DH, DH3	ASTM A563 Grade DH	ASTM A563 Grade C3, DH3	ASTM F436 Type 1	ASTM F436 Type 3