US Recommended Bolt Torque

Size Recommended Torque
Grade 2 Grade 5 Grade 8 18-8 S/S Bronze Brass
Coarse Fine Coarse Fine Coarse Fine Coarse Fine Coarse Fine Coarse Fine
#4* - - - - - - 5.2 - 4.8 - 4.3 -
#6* - - - - - - 9.6 - 8.9 - 7.9 -
#8* - - - - - - 19.8 - 18.4 - 16.2 -
#10* - - - - - - 22.8 31.7 21.2 29.3 18.6 25.9
1/4" 4 4.7 6.3 7.3 9 10 6.3 7.8 5.7 7.3 5.1 6.4
5/16" 8 9 13 14 18 20 11 11.8 10.3 10.9 8.9 9.7
3/8" 15 17 23 26 33 37 20 22 18 20 16 18
7/16" 24 27 37 41 52 58 31 33 29 31 26 27
1/2" 37 41 57 64 80 90 43 45 40 42 35 37
9/16" 53 59 82 91 115 129 57 63 53 58 47 51
5/8" 73 83 112 128 159 180 93 104 86 96 76 85
3/4" 125 138 200 223 282 315 128 124 104 102 118 115
7/8" 129 144 322 355 454 501 194 193 178 178 159 158
1" 188 210 483 541 682 764 287 289 265 240 235 212
* Sizes from #4 to #10 are in lb-in.
Sizes from 1/4" up are in lb-ft.
† Fine thread figures are for 1"-14.
Grade 2, 5, and 8 values are for slightly lubricated bolts.