Miscellaneous—Machine
OUT1739,0000250 –19–16JUN06–1/1
Unified Inch Bolt and Cap Screw Torque Values
TORQ1A –UN–27SEP99
Top, SAE Grade And Head Markings; Bottom, SAE Grade And Nut Markings
Grade 1 (No Mark) Grade 2
a
(No Mark) Grade 5, 5.1 or 5.2 Grade 8 or 8.2
Size Lubricated
b
Dry
c
Lubricated
b
Dry
c
Lubricated
b
Dry
c
Lubricated
b
Dry
c
N•m(lb-ft) N•m(lb-ft) N•m(lb-ft) N•m(lb-ft) N•m(lb-ft) N•m(lb-ft) N•m(lb-ft) 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 Make sure fastener threads are clean and that you properly start
procedure is given for a specific application. Torque values listed are thread engagement. This will prevent them from failing when
for general use only. Check tightness of fasteners periodically. tightening.
Shear bolts are designed to fail under predetermined loads. Always Tighten plastic insert or crimped steel-type lock nuts to approximately
replace shear bolts with identical grade. 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.
4-1-14
081407
PN=170
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