Strength Properties Specifications for Steel Bolts

Hardware ANSI Menu | Torque Design Menu
Strength of Materials

ASTM A490 series bolts are equivalent to ASTM A325 bolts in application and geometry, but are made to a higher strength. The imperial grades are made to the same strength specifications as ASTM A354 grade BD. The metric grades are made to the same strength specifications as ASTM F568M property class 10.9. Also, unlike their weaker counterparts they cannot be coated by hot-dip galvanization, mechanical deposition, or electroplating.

Because these bolts are designed to be used in structural applications the threaded length of the bolts are shorter to keep the threads out of the joint.

ASTM Designation No.	Size Range, Inclusive in. (mm)	Minimum Proof Strength, kpsi	Minimum Tensile Strength, kpsi	Minimum Yield Strength, kpsi	Material
A307	.25-1.5	33	60	36	Low Carbon
A325, Type 1	0.5-1.0, 1.125-1.4	85, 74	120, 105	92, 81	Medium Carbon, Q&T
A325, Type 2	0.5-1.0, 1.125-1.5	85, 75	120, 106	92, 82	Low Carbon Martensite, Q&T
A325, Type 3	0.5-1.0, 1.125-1.6	85, 76	120, 107	92, 83	Weathering Steel, Q&T
A354, Grade BC					Alloy Steel, Q&T
A354, Grade BD	0.25-4.0	120	150	130	Alloy Steel, Q&T
A449	0.25-1.0, 1.125-1.5, 1.75-3.0	85, 74, 55	120, 105, 90	92, 81, 58	Medium Carbon, Q&T
ASTM 490, Type 1	0.5 - 1.5	120	150 Min. 173 Ma	130	Alloy Steel, Q&T
ASTM 490, Type 2	0.5 - 1.0	120	150 Min. 173 Max.	130
ASTM 490, Type 3	0.5 - 1.5	120	150 Min. 173 Ma	130	Weathering Steel, Q&T
ASTM A490M, Type 1	12 - 36 (mm)	120 MPa	1040 MPa	940 MPa	-
ASTM A490M, Type 2 (Withdrawn)					-
ASTM A490M, Type 3					-

ASTM A490 and ASTM A490M are ASTM International standards for heavy hex structural bolts made from alloy steel. The imperial standard is officially titled Standard Specification for Structural Bolts, Alloy Steel, Heat Treated, 150 ksi Minimum Tensile Strength, while the metric standard (M) is titled Standard Specification for High-Strength Steel Bolts, Classes 10.9 and 10.9.3, for Structural Steel Joints.

Related Resources: