ASTM A 490 Heat Treated Alloy Steel Structural Bolts

ASTM A490 Specification for Heat Treated Alloy Steel Structural Bolts, 150 ksi Minimum Tensile Strength

Bolt Type denoting chemical composition

Type Description
Type 1 Medium carbon alloy steel
Type 2 Withdrawn in 2002
Type 3 Weathering steel

Chemical Requirements for Type 1 Bolts

Element Heat Analysis,% Product Analysis, %
Carbon
   For sizes through 13⁄8 in. 0.30–0.48 0.28–0.50
   For size 11⁄2 in. 0.35–0.53 0.33–0.55
Phosphorus, max 0.040 0.045
Sulfur, max 0.040 0.045

Chemical Requirements for Type 3 Bolts

Element Heat Analysis, % Product Analysis, %
Carbon
   Sizes 0.75 in. and smaller 0.20–0.53 0.19–0.55
   Sizes larger than 0.75 in. 0.30–0.53 0.28–0.55
Manganese, min 0.40 0.37
Phosphorus, max 0.035 0.040
Sulfur, max 0.040 0.045
Copper 0.20–0.60 0.17–0.63
Chromium, min 0.45 0.42
Nickel, min 0.20 0.17
or
Molybdenum, min 0.15 0.14

Hardness Requirements for Bolts 1/2 to 1-1/2 in. Nominal Size

Size, in. Length,in. Brinell Rockwell C
min max min max
1⁄2 to 1, incl. Less than 2 DA 311 352 33 39
2 DA and longer . . . 352 . . . 39
Over 1 to 11⁄2 , incl. Less than 3 DA 311 352 33 39
3 DA and longer . . . 352 . . . 39

Tensile Load Requirements for Full-Size Bolts

Bolt Size, Threads per Inch, and Series Designation

Stress Area, A in.2

 Tensile Load, B lbf Proof Load, B
lbf		 Alternative Proof Load, B lbf
min max Length Measurement
Method		 Yield Strength
Method
Column 1 Column 2 Column 3 Column 4 Column 5 Column 6
1⁄2-13 UNC 0.142 21 300 24 600 17 050 18 500
5⁄8-11 UNC 0.226 33 900 39 100 27 100 29 400
3⁄4-10 UNC 0.334 50 100 57 800 40 100 43 400
7⁄8-9 UNC 0.462 69 300 79 950 55 450 60 100
1-8 UNC 0.606 90 900 104 850 72 700 78 800
11⁄8-7 UNC 0.763 114 450 132 000 91 550 99 200
11⁄8-8 UN 0.790 118 500 136 700 94 800 102 700
11⁄4-7 UNC 0.969 145 350 167 650 116 300 126 000
11⁄4-8 UN 1.000 150 000 173 000 120 000 130 000
13⁄8-6 UNC 1.155 173 250 199 850 138 600 150 200
13⁄8-8 UN 1.233 185 000 213 350 148 000 160 300
11⁄2-6 UNC 1.405 210 750 243 100 168 600 182 600
11⁄2-8 UN 1.492 223 800 258 150 179 000 194 000
A The stress area is calculated as follows: As = 0.7854 [ D- (0.9743/n)]2
where: As = stress area, in.2; D = nominal bolt size; and n = threads per inch.

B Loads tabulated and loads to be used for tests of full-size bolts larger than 11.2 in. in diameter are based on the following:
Bolt Size Column 3 Column 4 Column 5 Column 6
1.2 to 11.2 in., incl 150 000 psi 173 000 psi 120 000 psi 130 000 psi