Thelen Tree Farm

Celebrating 17 Years - 2001 ~ 2018  



Bolt Torque - Screw Torque Data

Suggested maxium torque values for different material and grade bolts & screws.

Torque, is the measurement of the turning or twisting force applied to an object. The desired result is to hold two parts together with a tension or clamping force that is greater than any external force that could possibly seperate them. The part then remains under constant stress and is immune to fatigue.

These charts apply to clean and dry parts. A lubricated bolt requires less torque to attain the same clamping force as a non-lubricated bolt.

The values are stated in Inch pounds.
Bolt Size Thds Per Inch Low Carbon Steel 18-8 St. St. Yellow Brass Silicon Bronze Aluminum 2024-T4 316 St. St. Monel
0 80 1.0 --- --- --- --- --- ---
1 64 1.5 --- --- --- --- --- ---
72 2.0 --- --- --- --- --- ---
2 56 2.2 2.5 2.0 2.3 1.4 2.6 2.5
64 2.7 3.0 2.5 2.8 1.4 3.2 3.1
3 48 3.5 3.9 3.2 3.6 2.1 4.0 4.0
56 4.0 4.4 3.6 4.1 2.4 4.6 4.5
4 40 4.7 5.2 4.3 4.8 2.9 5.5 5.3
48 5.9 6.6 5.4 6.1 3.6 6.9 6.7
5 40 6.9 7.7 6.3 7.1 4.2 8.1 7.8
44 8.5 9.4 7.7 8.7 5.1 9.8 9.6
6 32 8.7 9.6 7.9 8.9 5.3 10.1 9.8
40 10.9 12.1 9.9 11.2 6.6 12.7 12.3
8 32 17.8 19.8 16.2 18.4 10.8 20.7 20.2
36 19.8 22.0 18.0 20.4 12.0 23.0 22.4
10 24 20.8 22.8 18.6 21.2 13.8 23.8 25.9
32 29.7 31.7 25.9 29.3 19.2 33.1 34.9
12 24 --- --- --- --- --- --- ---
28 --- --- --- --- --- --- ---
1/4 20 65.0 75.2 61.5 68.8 45.6 78.8 85.3
28 90.0 94.0 77.0 87.0 57.0 99.0 106.0
5/16 18 129 132 107 123 80 138 149
24 139 142 116 131 86 147 160
3/8 16 212 236 192 219 143 247 266
24 232 259 212 240 157 271 297
7/16 14 338 376 317 349 228 393 427
20 361 400 327 371 242 418 451
1/2 13 465 517 422 480 313 542 584
20 487 541 443 502 328 565 613
9/16 12 613 682 558 632 413 713 774
18 668 752 615 697 456 787 855
5/8 11 1000 1110 907 1030 715 1160 1330
18 1140 1244 1016 1154 798 1301 1492
3/4 10 1259 1530 1249 1416 980 1582 1832
16 1230 1490 1220 1382 958 1558 1790
7/8 9 1919 2328 1905 2140 1495 2430 2775
14 1911 2318 1895 2130 1490 2420 2755
1 8 2832 3440 2815 3185 2205 3595 4130
14 2562 3110 2545 2885 1995 3250 3750


The values are stated in foot pounds.
Bolt Size (inches)
Thds Per Inch
ttc
SAE 0-1-2
74,000 psi Low Carbon Steel
SAE Grade 3
100,000 psi Med Carbon Steel
SAE Grade 5
120,000 psi Med Carbon Heat T. Steel
SAE Grade 6
133,000 psi Med Carbon Temp. Steel
SAE Grade 7
133,000 psi Med Carbon Alloy Steel
SAE Grade 8
150,000 psi Med Carbon Alloy Steel
1/4 20 6 9 10 12.5 13 14
28 --- --- --- --- --- ---
5/16 18 12 17 19 24 25 29
24 --- --- --- --- --- ---
3/8 16 20 30 33 43 44 47
24 --- --- --- --- --- ---
7/16 14 32 47 54 69 71 78
20 --- --- --- --- --- ---
1/2 13 47 69 78 106 110 119
20 --- --- --- --- --- ---
9/16 12 69 103 114 150 154 169
18 --- --- --- --- --- ---
5/8 11 96 145 154 209 215 230
11 --- --- --- --- --- ---
3/4 10 155 234 257 350 360 380
10 --- --- --- --- --- ---
7/8 9 206 372 382 550 570 600
9 --- --- --- --- --- ---
1 8 310 551 587 825 840 700
8 --- --- --- --- --- ---
1-1/8 7 480 794 872 1304 1325 1430
7 --- --- --- --- --- ---
1-1/4 7 375 1105 1211 1815 1825 1975
7 --- --- --- --- --- ---
1-3/8 6 900 1500 1624 2434 2500 2650
6 --- --- --- --- --- ---
1-1/2 6 1100 1775 1943 2913 3000 3200
6 --- --- --- --- --- ---
1-5/8 5.5 1470 2425 2660 3985 4000 4400
5.5 --- --- --- --- --- ---
1-3/4 5 1900 3150 3463 5189 5300 5650
5 --- --- --- --- --- ---
1-7/8 5 2360 4200 4695 6980 7000 7600
5 --- --- --- --- --- ---
2 4.5 2750 4550 5427 7491 7500 8200
4.5 --- --- --- --- --- ---