Unified Inch Bolt and Cap Screw Torque Values

TS1162

  Grade 1 a Grade 2 b Grade 5, 5.1, or 5.2 Grade 8 or 8.2
  Lubricated c Dry d Lubricated c Dry d Lubricated c Dry d Lubricated c Dry d
Size Nm lb-ft Nm lb-ft Nm lb-ft Nm lb-ft Nm lb-ft Nm lb-ft Nm lb-ft Nm lb-ft
1/4 3.7 2.8 4.7 3.5 6 4.5 7.5 5.5 9.5 7 12 9 13.5 10 17 12.5
5/16 7.7 5.5 10 7 12 9 15 11 20 15 25 18 28 21 35 26
3/8 14 10 17 13 22 16 27 20 35 26 44 33 50 36 63 46
7/16 22 16 28 20 35 26 44 32 55 41 70 52 80 58 100 75
1/2 33 25 42 31 53 39 67 50 85 63 110 80 120 90 150 115
9/16 48 36 60 45 75 56 95 70 125 90 155 115 175 130 225 160
5/8 67 50 85 62 105 78 135 100 170 125 215 160 240 175 300 225
3/4 120 87 150 110 190 140 240 175 300 225 375 280 425 310 550 400
7/8 190 140 240 175 190 140 240 175 490 360 625 450 700 500 875 650
1 290 210 360 270 290 210 360 270 725 540 925 675 1050 750 1300 975
1-1/8 400 300 510 375 400 300 510 375 900 675 1150 850 1450 1075 1850 1350
1-1/4 570 425 725 530 570 425 725 530 1300 950 1650 1200 2050 1500 2600 1950
1-3/8 750 550 950 700 750 550 950 700 1700 1250 2150 1550 2700 2000 3400 2550
1-1/2 1000 725 1250 925 990 725 1250 930 2250 1650 2850 2100 3600 2650 4550 3350
aGrade 1 applies for hex cap screws over152 mm (6-in.) long, and for all other types of bolts and screws of any length.
bGrade 2 applies for hex cap screws (not hex bolts) up to 152 mm (6 in.) long.
c"Lubricated" means coated with a lubricant such as engine oil, or fasteners with phosphate and oil coatings.
d"Dry" means plain or zinc plated without any lubrication.

 

DO NOT use these values if a different torque value or tightening procedure is given for a specific application. Torque values listed are for general use only. Check tightness of fasteners periodically.

Shear bolts are designed to fail under predetermined loads. Always replace shear bolts with identical grade.

DX,TORQ1 -19-20JUL94-1/2

Fasteners should be replaced with the same or higher grade. If higher grade fasteners are used, these should only be tightened to the strength of the original.

Make sure fasteners threads are clean and that you properly start thread engagement. This will prevent them from failing when tightening.

Tighten plastic insert or crimped steel-type lock nuts to approximately 50 percent of the dry torque shown in the chart, applied to the nut, not to the bolt head. Tighten toothed or serrated-type lock nuts to the full torque value.

DX,TORQ1 -19-20JUL94-2/2