TorqueMath.com · Bolt Torque Charttorquemath.com/bolt-torque-chart/
This chart answers the everyday question: how tight? Every torque value tightens the bolt to 75 % of its proof load, a usual target for joints you may open again, and the preload column shows the clamp force that gives. Friction changes the answer more than anything else: a waxed or moly-coated bolt needs only half the torque of a dry one for the same clamp force. Choose the nut factor K for your thread finish – the tables switch to it, and print with it.
Metric coarse thread (ISO)
Thread finish (nut factor K)
K = 0.20 (Dry steel / Zinc plated)
| Size | Pitch mm | As mm² | 8.8 | 10.9 | 12.9 | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Preload kN | Torque N·m | Torque N·m | Torque N·m | Torque N·m | Torque N·m | Preload kN | Torque N·m | Torque N·m | Torque N·m | Torque N·m | Torque N·m | Preload kN | Torque N·m | Torque N·m | Torque N·m | Torque N·m | Torque N·m | |||
| M3 | 0.5 | 5.03 | 2.2 | 1.31 | 1.18 | 1.05 | 0.85 | 0.66 | 3.1 | 1.88 | 1.69 | 1.50 | 1.22 | 0.94 | 3.7 | 2.20 | 1.98 | 1.76 | 1.43 | 1.10 |
| M4 | 0.7 | 8.78 | 3.8 | 3.06 | 2.75 | 2.44 | 1.99 | 1.53 | 5.5 | 4.37 | 3.94 | 3.50 | 2.84 | 2.19 | 6.4 | 5.11 | 4.60 | 4.09 | 3.32 | 2.55 |
| M5 | 0.8 | 14.2 | 6.2 | 6.18 | 5.56 | 4.94 | 4.02 | 3.09 | 8.8 | 8.84 | 7.96 | 7.07 | 5.75 | 4.42 | 10.3 | 10.3 | 9.30 | 8.26 | 6.71 | 5.17 |
| M6 | 1 | 20.1 | 8.7 | 10.5 | 9.44 | 8.39 | 6.82 | 5.25 | 12.5 | 15.0 | 13.5 | 12.0 | 9.76 | 7.51 | 14.6 | 17.5 | 15.8 | 14.0 | 11.4 | 8.77 |
| M8 | 1.25 | 36.6 | 15.9 | 25.5 | 22.9 | 20.4 | 16.6 | 12.7 | 22.8 | 36.5 | 32.8 | 29.2 | 23.7 | 18.2 | 26.6 | 42.6 | 38.3 | 34.1 | 27.7 | 21.3 |
| M10 | 1.5 | 58 | 25.2 | 50.5 | 45.4 | 40.4 | 32.8 | 25.2 | 36.1 | 72.2 | 65.0 | 57.8 | 46.9 | 36.1 | 42.2 | 84.4 | 76.0 | 67.5 | 54.9 | 42.2 |
| M12 | 1.75 | 84.3 | 36.7 | 88.0 | 79.2 | 70.4 | 57.2 | 44.0 | 52.5 | 125.9 | 113.3 | 100.8 | 81.9 | 63.0 | 61.3 | 147.2 | 132.5 | 117.8 | 95.7 | 73.6 |
| M14 | 2 | 115 | 50.0 | 140.1 | 126.1 | 112.1 | 91.0 | 70.0 | 71.6 | 200.4 | 180.4 | 160.4 | 130.3 | 100.2 | 83.7 | 234.3 | 210.8 | 187.4 | 152.3 | 117.1 |
| M16 | 2 | 157 | 68.3 | 218.5 | 196.7 | 174.8 | 142.1 | 109.3 | 97.7 | 312.7 | 281.5 | 250.2 | 203.3 | 156.4 | 114.2 | 365.5 | 328.9 | 292.4 | 237.6 | 182.7 |
| M20 | 2.5 | 245 | 110.3 | 441.0 | 396.9 | 352.8 | 286.6 | 220.5 | 152.5 | 610.0 | 549.0 | 488.0 | 396.5 | 305.0 | 178.2 | 713.0 | 641.7 | 570.4 | 463.4 | 356.5 |
| M24 | 3 | 353 | 158.8 | 762.5 | 686.2 | 610.0 | 495.6 | 381.2 | 219.7 | 1054.8 | 949.3 | 843.8 | 685.6 | 527.4 | 256.8 | 1232.7 | 1109.4 | 986.1 | 801.2 | 616.3 |
| M30 | 3.5 | 561 | 252.4 | 1514.7 | 1363.2 | 1211.8 | 984.6 | 757.4 | 349.2 | 2095.3 | 1885.8 | 1676.3 | 1362.0 | 1047.7 | 408.1 | 2448.8 | 2203.9 | 1959.0 | 1591.7 | 1224.4 |
Metric fine thread (ISO)
K = 0.20 (Dry steel / Zinc plated)
| Size | Pitch mm | As mm² | 8.8 | 10.9 | 12.9 | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Preload kN | Torque N·m | Torque N·m | Torque N·m | Torque N·m | Torque N·m | Preload kN | Torque N·m | Torque N·m | Torque N·m | Torque N·m | Torque N·m | Preload kN | Torque N·m | Torque N·m | Torque N·m | Torque N·m | Torque N·m | |||
| M8 | 1 | 39.2 | 17.1 | 27.3 | 24.6 | 21.8 | 17.7 | 13.6 | 24.4 | 39.0 | 35.1 | 31.2 | 25.4 | 19.5 | 28.5 | 45.6 | 41.1 | 36.5 | 29.7 | 22.8 |
| M10 | 1.25 | 61.2 | 26.6 | 53.2 | 47.9 | 42.6 | 34.6 | 26.6 | 38.1 | 76.2 | 68.6 | 61.0 | 49.5 | 38.1 | 44.5 | 89.0 | 80.1 | 71.2 | 57.9 | 44.5 |
| M12 | 1.25 | 92.1 | 40.1 | 96.2 | 86.5 | 76.9 | 62.5 | 48.1 | 57.3 | 137.6 | 123.8 | 110.1 | 89.4 | 68.8 | 67.0 | 160.8 | 144.7 | 128.6 | 104.5 | 80.4 |
| M14 | 1.5 | 125 | 54.4 | 152.3 | 137.0 | 121.8 | 99.0 | 76.1 | 77.8 | 217.9 | 196.1 | 174.3 | 141.6 | 108.9 | 90.9 | 254.6 | 229.2 | 203.7 | 165.5 | 127.3 |
| M16 | 1.5 | 167 | 72.6 | 232.5 | 209.2 | 186.0 | 151.1 | 116.2 | 104.0 | 332.7 | 299.4 | 266.1 | 216.2 | 166.3 | 121.5 | 388.8 | 349.9 | 311.0 | 252.7 | 194.4 |
| M20 | 1.5 | 272 | 122.4 | 489.6 | 440.6 | 391.7 | 318.2 | 244.8 | 169.3 | 677.3 | 609.6 | 541.8 | 440.2 | 338.6 | 197.9 | 791.5 | 712.4 | 633.2 | 514.5 | 395.8 |
| M24 | 2 | 384 | 172.8 | 829.4 | 746.5 | 663.6 | 539.1 | 414.7 | 239.0 | 1147.4 | 1032.7 | 917.9 | 745.8 | 573.7 | 279.4 | 1340.9 | 1206.8 | 1072.7 | 871.6 | 670.5 |
| M30 | 2 | 621 | 279.4 | 1676.7 | 1509.0 | 1341.4 | 1089.9 | 838.4 | 386.6 | 2319.4 | 2087.5 | 1855.5 | 1507.6 | 1159.7 | 451.8 | 2710.7 | 2439.6 | 2168.5 | 1761.9 | 1355.3 |
UNC – Unified coarse (SAE J429)
K = 0.20 (Dry steel / Zinc plated)
| Size | TPI | As mm² | Grade 5 | Grade 8 | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Preload kN | Torque N·m (ft·lb) | Torque N·m (ft·lb) | Torque N·m (ft·lb) | Torque N·m (ft·lb) | Torque N·m (ft·lb) | Preload kN | Torque N·m (ft·lb) | Torque N·m (ft·lb) | Torque N·m (ft·lb) | Torque N·m (ft·lb) | Torque N·m (ft·lb) | |||
| 1/4" | 20 | 20.5 | 9.0 | 11.4 (8.4) | 10.3 (7.6) | 9.15 (6.8) | 7.44 (5.5) | 5.72 (4.2) | 12.7 | 16.1 (11.9) | 14.5 (10.7) | 12.9 (9.5) | 10.5 (7.7) | 8.07 (6.0) |
| 5/16" | 18 | 33.8 | 14.9 | 23.6 (17.4) | 21.2 (15.7) | 18.9 (13.9) | 15.3 (11.3) | 11.8 (8.7) | 21.0 | 33.3 (24.6) | 30.0 (22.1) | 26.6 (19.6) | 21.6 (16.0) | 16.6 (12.3) |
| 3/8" | 16 | 50 | 22.0 | 41.9 (30.9) | 37.7 (27.8) | 33.5 (24.7) | 27.2 (20.1) | 20.9 (15.4) | 31.0 | 59.1 (43.6) | 53.2 (39.2) | 47.3 (34.9) | 38.4 (28.3) | 29.5 (21.8) |
| 7/16" | 14 | 68.6 | 30.1 | 67.0 (49.4) | 60.3 (44.5) | 53.6 (39.5) | 43.5 (32.1) | 33.5 (24.7) | 42.5 | 94.5 (69.7) | 85.1 (62.8) | 75.6 (55.8) | 61.5 (45.3) | 47.3 (34.9) |
| 1/2" | 13 | 91.5 | 40.2 | 102.1 (75.3) | 91.9 (67.8) | 81.7 (60.3) | 66.4 (49.0) | 51.1 (37.7) | 56.8 | 144.2 (106.3) | 129.7 (95.7) | 115.3 (85.1) | 93.7 (69.1) | 72.1 (53.2) |
| 9/16" | 12 | 117 | 51.4 | 147.0 (108.4) | 132.3 (97.6) | 117.6 (86.7) | 95.5 (70.5) | 73.5 (54.2) | 72.6 | 207.4 (153.0) | 186.7 (137.7) | 165.9 (122.4) | 134.8 (99.4) | 103.7 (76.5) |
| 5/8" | 11 | 146 | 64.2 | 203.7 (150.3) | 183.4 (135.2) | 163.0 (120.2) | 132.4 (97.7) | 101.9 (75.1) | 90.6 | 287.5 (212.1) | 258.8 (190.9) | 230.0 (169.6) | 186.9 (137.8) | 143.8 (106.0) |
| 3/4" | 10 | 215 | 94.5 | 360.0 (265.5) | 324.0 (239.0) | 288.0 (212.4) | 234.0 (172.6) | 180.0 (132.8) | 133.4 | 508.1 (374.7) | 457.3 (337.3) | 406.5 (299.8) | 330.3 (243.6) | 254.0 (187.4) |
| 7/8" | 9 | 298 | 131.0 | 582.3 (429.5) | 524.1 (386.5) | 465.8 (343.6) | 378.5 (279.2) | 291.1 (214.7) | 184.8 | 821.8 (606.1) | 739.6 (545.5) | 657.4 (484.9) | 534.2 (394.0) | 410.9 (303.1) |
| 1" | 8 | 391 | 171.8 | 873.0 (643.9) | 785.7 (579.5) | 698.4 (515.1) | 567.4 (418.5) | 436.5 (321.9) | 242.5 | 1232.0 (908.7) | 1108.8 (817.8) | 985.6 (726.9) | 800.8 (590.6) | 616.0 (454.3) |
UNF – Unified fine (SAE J429)
K = 0.20 (Dry steel / Zinc plated)
| Size | TPI | As mm² | Grade 5 | Grade 8 | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Preload kN | Torque N·m (ft·lb) | Torque N·m (ft·lb) | Torque N·m (ft·lb) | Torque N·m (ft·lb) | Torque N·m (ft·lb) | Preload kN | Torque N·m (ft·lb) | Torque N·m (ft·lb) | Torque N·m (ft·lb) | Torque N·m (ft·lb) | Torque N·m (ft·lb) | |||
| 1/4" | 28 | 23.5 | 10.3 | 13.1 (9.7) | 11.8 (8.7) | 10.5 (7.7) | 8.53 (6.3) | 6.56 (4.8) | 14.6 | 18.5 (13.7) | 16.7 (12.3) | 14.8 (10.9) | 12.0 (8.9) | 9.26 (6.8) |
| 5/16" | 24 | 37.4 | 16.4 | 26.1 (19.3) | 23.5 (17.3) | 20.9 (15.4) | 17.0 (12.5) | 13.1 (9.6) | 23.2 | 36.8 (27.2) | 33.2 (24.5) | 29.5 (21.7) | 23.9 (17.7) | 18.4 (13.6) |
| 3/8" | 24 | 56.6 | 24.9 | 47.4 (35.0) | 42.6 (31.5) | 37.9 (28.0) | 30.8 (22.7) | 23.7 (17.5) | 35.1 | 66.9 (49.3) | 60.2 (44.4) | 53.5 (39.5) | 43.5 (32.1) | 33.4 (24.7) |
| 7/16" | 20 | 76.6 | 33.7 | 74.8 (55.2) | 67.3 (49.7) | 59.8 (44.1) | 48.6 (35.9) | 37.4 (27.6) | 47.5 | 105.6 (77.9) | 95.0 (70.1) | 84.5 (62.3) | 68.6 (50.6) | 52.8 (38.9) |
| 1/2" | 20 | 103 | 45.3 | 115.0 (84.8) | 103.5 (76.3) | 92.0 (67.8) | 74.7 (55.1) | 57.5 (42.4) | 63.9 | 162.3 (119.7) | 146.0 (107.7) | 129.8 (95.7) | 105.5 (77.8) | 81.1 (59.8) |
| 9/16" | 18 | 131 | 57.6 | 164.5 (121.4) | 148.1 (109.2) | 131.6 (97.1) | 107.0 (78.9) | 82.3 (60.7) | 81.3 | 232.2 (171.3) | 209.0 (154.1) | 185.8 (137.0) | 150.9 (111.3) | 116.1 (85.6) |
| 5/8" | 18 | 165 | 72.5 | 230.2 (169.8) | 207.2 (152.8) | 184.2 (135.9) | 149.7 (110.4) | 115.1 (84.9) | 102.3 | 324.9 (239.7) | 292.4 (215.7) | 259.9 (191.7) | 211.2 (155.8) | 162.5 (119.8) |
| 3/4" | 16 | 240 | 105.5 | 401.9 (296.4) | 361.7 (266.8) | 321.5 (237.1) | 261.2 (192.7) | 200.9 (148.2) | 148.9 | 567.2 (418.3) | 510.4 (376.5) | 453.7 (334.6) | 368.7 (271.9) | 283.6 (209.2) |
| 7/8" | 14 | 329 | 144.6 | 642.9 (474.2) | 578.6 (426.7) | 514.3 (379.3) | 417.9 (308.2) | 321.4 (237.1) | 204.1 | 907.3 (669.2) | 816.5 (602.2) | 725.8 (535.3) | 589.7 (435.0) | 453.6 (334.6) |
| 1" | 12 | 428 | 188.1 | 955.6 (704.8) | 860.0 (634.3) | 764.5 (563.8) | 621.1 (458.1) | 477.8 (352.4) | 265.5 | 1348.6 (994.7) | 1213.7 (895.2) | 1078.9 (795.7) | 876.6 (646.5) | 674.3 (497.3) |
Assumptions and sources
- Torque T = K × F × d with preload F = 75 % of the proof load (proof stress × stress area As), the calculator's default. This short-form method is not a VDI 2230 joint calculation.
- Proof stress (ISO 898-1): 8.8 = 580 MPa up to M16 and 600 MPa above, 10.9 = 830 MPa, 12.9 = 970 MPa. SAE J429: Grade 5 = 586 MPa (85 ksi), Grade 8 = 827 MPa (120 ksi).
- Stress areas As from ISO 898-1 (metric) and ASME B1.1 (UNC/UNF), as listed in the table.
- Nut factor K by finish, as in the calculator: dry steel and zinc plated 0.20, lightly oiled 0.18, black oxide oiled 0.16, moly paste or anti-seize 0.13, waxed or PTFE 0.10.
- Tightening by torque gives about ±25 % preload scatter. For critical joints use the bolt or equipment maker's values, angle tightening or a calibrated method.
- Generated from the same code as the calculator: Bolt Torque Calculator · TorqueMath v2.10 · How this calculator was checked
Need a size or setting that is not in the chart?The calculator takes your own K factor and preload percentage and adds bolt stretch, the force on the wrench and classes 4.6, 5.8 and Grade 2.
Calculate for your exact case →
Click torque wrench 1/2"