Strength Properties Specifications for Steel Bolts

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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ASTM A490M, Type 2 (Withdrawn)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.

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