Page 158 - GarlockFluidSealing2010

D-40
The torque required to produce a certain stress in
bolting is dependent on several conditions, including:
¦Diameter and number of threads on bolt
¦Condition of nut bearing surfaces
¦Lubrication of bolt threads and nut bearing surfaces.
The tables below refect the results of many tests to
determine the relation between torque and bolt stress. Val-
1/4 20 0.185 0.027 4 810 6 1215 8 1620
5/16 18 0.240 0.045 8 1350 12 2025 16 2700
3/8 16 0.294 0.068 12 2040 18 3060 24 4080
7/16 14 0.345 0.093 20 2790 30 4185 40 5580
1/2 13 0.400 0.126 30 3780 45 5670 60 7560
9/16 12 0.454 0.162 45 4860 68 7290 90 9720
5/8 11 0.507 0.202 60 6060 90 9090 120 12120
3/4 10 0.620 0.302 100 9060 150 13590 200 18120
7/8 9 0.731 0.419 160 12570 240 18855 320 25140
1 8 0.838 0.551 245 16530 368 24795 490 33060
1-1/8 8 0.963 0.728 355 21840 533 32760 710 43680
1-1/4 8 1.088 0.929 500 27870 750 41805 1000 55740
1-3/8 8 1.213 1.155 680 34650 1020 51975 1360 69300
1-1/2 8 1.338 1.405 800 42150 1200 63225 1600 84300
1-5/8 8 1.463 1.680 1100 50400 1650 75600 2200 100800
1-3/4 8 1.588 1.980 1500 59400 2250 89100 3000 118800
1-7/8 8 1.713 2.304 2000 69120 3000 103680 4000 138240
2 8 1.838 2.652 2200 79560 3300 119340 4400 159120
2-1/4 8 2.088 3.423 3180 102690 4770 154035 6360 205380
2-1/2 8 2.338 4.292 4400 128760 6600 193140 8800 257520
2-3/4 8 2.588 5.259 5920 157770 8880 236655 11840 315540
3 8 2.838 6.324 7720 189720 11580 264580 15440 379440
ues are based on steel bolts that have been well-lubricated
with a heavy graphite and oil mixture.
A non-lubricated bolt has an effciency of about 50%
of a well-lubricated bolt. Also, different lubricants produce
results that vary from 50% to 100% of the tabulated stress
fgures.
Torque to Stress Bolts
Nominal Number Diameter Stress
Diameter of at Root Area at Root 30,000 psi 45,000 psi 60,000 psi
of Bolt Threads of Thread of Thread Torque Compres- Torque Compres- Torque Compres-
(inches) (per inch) (inches) (sq. inch) (ft lbs) sion (lbs) (ft lbs) sion (lbs) (ft lbs) sion (lbs)
Nominal Number Diameter Stress
Diameter of at Root Area at Root 7,500 psi 15,000 psi 30,000 psi
of Bolt Threads of Thread of Thread Torque Compres- Torque Compres- Torque Compres-
(inches) (per inch) (inches) (sq. inch) (ft lbs) sion (lbs) (ft lbs) sion (lbs) (ft lbs) sion (lbs)
For Machine Bolts and Cold Rolled Steel Stud Bolts (Load in pounds on stud bolts when torque load is applied)
For Alloy Steel Stud Bolts (Load in pounds on stud bolts when torque load is applied)
1/4 20 0.185 0.027 1 203 2 405 4 810
5/16 18 0.240 0.045 2 338 4 675 8 1350
3/8 16 0.294 0.068 3 510 6 1020 12 2040
7/16 14 0.345 0.093 5 698 10 1395 20 2790
1/2 13 0.400 0.126 8 945 15 1890 30 3780
9/16 12 0.454 0.162 12 1215 23 2340 45 4860
5/8 11 0.507 0.202 15 1515 30 3030 60 6060
3/4 10 0.620 0.302 25 2265 50 4530 100 9060
7/8 9 0.731 0.419 40 3143 80 6285 160 12570
1 8 0.838 0.551 62 4133 123 8265 245 16530
1-1/8 7 0.939 0.693 98 5190 195 10380 390 20760
1-1/4 7 1.064 0.890 137 6675 273 13350 545 26700
1-3/8 6 1.158 1.054 183 7905 365 15810 730 31620
1-1/2 6 1.283 1.294 219 9705 437 19410 875 38820
1-5/8 5-1/2 1.389 1.515 300 11363 600 22725 1200 45450
1-3/4 5 1.490 1.744 390 13080 775 26160 1550 52320
1-7/8 5 1.615 2.049 525 15368 1050 30735 2100 61470
2 4-1/2 1.711 2.300 563 17250 1125 34500 2250 69000