Unified Inch Bolt and Cap Screw Torque Values
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| Grade 1 (No Mark) | Grade 2a (No Mark) | Grade 5, 5.1 or 5.2 | Grade 8 or 8.2 | |||||
|---|---|---|---|---|---|---|---|---|
| Size | Lubricatedb N·m (lb-ft) | Dryc N·m (lb-ft) | Lubricatedb N·m (lb-ft) | Dryc N·m (lb-ft) | Lubricatedb N·m (lb-ft) | Dryc N·m (lb-ft) | Lubricatedb N·m (lb-ft) | Dryc N·m (lb-ft) |
| 1/4 | 3.8 (2.8) | 4.7 (3.5) | 6 (4.4) | 7.5 (5.5) | 9.5 (7) | 12 (9) | 13.5 (10) | 17 (12.5) |
| 5/16 | 7.7 (5.7) | 9.8 (7.2) | 12 (9) | 15.5 (11.5) | 19.5 (14.5) | 25 (18.5) | 28 (20.5) | 35 (26) |
| 3/8 | 13.5 (10) | 17.5 (13) | 22 (16) | 27.5 (20) | 35 (26) | 44 (32.5) | 49 (36) | 63 (46) |
| 7/16 | 22 (16) | 28 (20.5) | 35 (26) | 44 (32.5) | 56 (41) | 70 (52) | 80 (59) | 100 (74) |
| 1/2 | 34 (25) | 42 (31) | 53 (39) | 67 (49) | 85 (63) | 110 (80) | 120 (88) | 155 (115) |
| 9/16 | 48 (35.5) | 60 (45) | 76 (56) | 95 (70) | 125 (92) | 155 (115) | 175 (130) | 220 (165) |
| 5/8 | 67 (49) | 85 (63) | 105 (77) | 135 (100) | 170 (125) | 215 (160) | 240 (175) | 305 (225) |
| 3/4 | 120 (88) | 150 (110) | 190 (140) | 240 (175) | 300 (220) | 380 (280) | 425 (315) | 540 (400) |
| 7/8 | 190 (140) | 240 (175) | 190 (140) | 240 (175) | 490 (360) | 615 (455) | 690 (510) | 870 (640) |
| 1 | 285 (210) | 360 (265) | 285 (210) | 360 (265) | 730 (540) | 920 (680) | 1030 (760) | 1300 (960) |
| 1-1/8 | 400 (300) | 510 (375) | 400 (300) | 510 (375) | 910 (670) | 1150 (850) | 1450 (1075) | 1850 (1350) |
| 1-1/4 | 570 (420) | 725 (535) | 570 (420) | 725 (535) | 1280 (945) | 1630 (1200) | 2050 (1500) | 2600 (1920) |
| 1-3/8 | 750 (550) | 950 (700) | 750 (550) | 950 (700) | 1700 (1250) | 2140 (1580) | 2700 (2000) | 3400 (2500) |
| 1-1/2 | 990 (730) | 1250 (930) | 990 (730) | 1250 (930) | 2250 (1650) | 2850 (2100) | 3600 (2650) | 4550 (3350) |
| a Grade 2 applies for hex cap screws (not hex bolts) up to 6 in. (152 mm) long. Grade 1 applies for hex cap screws over 6 in. (152 mm) long, and for all other types of bolts and screws of any length. | ||||||||
| b "Lubricated" means coated with a lubricant such as engine oil, or fasteners with phosphate and oil coatings. | ||||||||
| c "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. | Make sure fastener threads are clean and that you properly start thread engagement. This will prevent them from failing when tightening. |
| Shear bolts are designed to fail under predetermined loads. Always replace shear bolts with identical grade. | 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. |
| 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. |
DX,TORQ1 -19-01OCT99-1/1 |