Unified Inch Bolt and Cap Screw Torque Values
TORQ1A-UN-15APR13
Top, SAE Grade and Head Markings; Bottom, SAE Grade and Nut Markings
|
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. |
|
TX17994,00002D3-19-20020311 |