SAE Grade 2 Bolt Torque Chart
Tightening torque and clamp force for SAE Grade 2 bolts from 1/4" to 1-1/2". For example, a 1/4" Grade 2 bolt needs about 5.60 ft·lb (7.59 N·m) with dry threads.
Low-carbon steel, unmarked head. General hardware-store bolts. Strength drops above 3/4" (SAE J429).
- Standard
- SAE J429 (inch)
- Yield strength used
- 393 MPa (57 ksi) up to 0.75", 248 MPa (36 ksi) over 0.75"
- Tensile strength
- 510 MPa (74 ksi)
- Sizes covered
- 1/4" – 1-1/2"
| Size | Threadpitch | Clamp forcepreload | Dryμ 0.15 | Oiledμ 0.11 | PTFE / moly pasteμ 0.06 |
|---|---|---|---|---|---|
| 1/4" | 1/4"-20 UNC20 TPI | 5.65 kN1270 lbf | 5.60 ft·lb7.59 N·m | 4.25 ft·lb5.76 N·m | 2.90 ft·lb3.93 N·m |
| 5/16" | 5/16"-18 UNC18 TPI | 9.31 kN2092 lbf | 11.1 ft·lb15.0 N·m | 8.35 ft·lb11.3 N·m | 5.65 ft·lb7.67 N·m |
| 3/8" | 3/8"-16 UNC16 TPI | 13.8 kN3092 lbf | 19.1 ft·lb25.9 N·m | 14.4 ft·lb19.5 N·m | 9.70 ft·lb13.2 N·m |
| 7/16" | 7/16"-14 UNC14 TPI | 18.9 kN4242 lbf | 30.0 ft·lb40.7 N·m | 22.6 ft·lb30.7 N·m | 15.3 ft·lb20.7 N·m |
| 1/2" | 1/2"-13 UNC13 TPI | 25.2 kN5662 lbf | 46.6 ft·lb63.2 N·m | 35.0 ft·lb47.5 N·m | 23.4 ft·lb31.8 N·m |
| 9/16" | 9/16"-12 UNC12 TPI | 32.3 kN7260 lbf | 66.2 ft·lb89.7 N·m | 49.7 ft·lb67.4 N·m | 33.2 ft·lb45.0 N·m |
| 5/8" | 5/8"-11 UNC11 TPI | 40.1 kN9017 lbf | 92.0 ft·lb124.7 N·m | 69.0 ft·lb93.5 N·m | 45.9 ft·lb62.3 N·m |
| 3/4" | 3/4"-10 UNC10 TPI | 59.4 kN13345 lbf | 161.8 ft·lb219.3 N·m | 120.9 ft·lb163.9 N·m | 80.0 ft·lb108.4 N·m |
| 7/8" | 7/8"-9 UNC9 TPI | 51.7 kN11626 lbf | 163.5 ft·lb221.7 N·m | 121.9 ft·lb165.3 N·m | 80.4 ft·lb109.0 N·m |
| 1" | 1"-8 UNC8 TPI | 67.8 kN15252 lbf | 244.5 ft·lb331.4 N·m | 182.2 ft·lb247.1 N·m | 120.0 ft·lb162.7 N·m |
| 1-1/8" | 1-1/8"-7 UNC7 TPI | 85.5 kN19218 lbf | 346.4 ft·lb469.7 N·m | 258.4 ft·lb350.4 N·m | 170.4 ft·lb231.0 N·m |
| 1-1/4" | 1-1/4"-7 UNC7 TPI | 108.5 kN24401 lbf | 484.8 ft·lb657.4 N·m | 360.3 ft·lb488.5 N·m | 235.8 ft·lb319.7 N·m |
| 1-3/8" | 1-3/8"-6 UNC6 TPI | 129.3 kN29078 lbf | 637.4 ft·lb864.2 N·m | 474.7 ft·lb643.6 N·m | 312.0 ft·lb423.0 N·m |
| 1-1/2" | 1-1/2"-6 UNC6 TPI | 157.4 kN35382 lbf | 840.8 ft·lb1140.0 N·m | 624.3 ft·lb846.4 N·m | 407.8 ft·lb552.9 N·m |
| Size | Threadpitch | Clamp forcepreload | Dryμ 0.15 | Oiledμ 0.11 | PTFE / moly pasteμ 0.06 |
|---|---|---|---|---|---|
| 1/4" | 1/4"-28 UNF28 TPI | 6.46 kN1451 lbf | 6.22 ft·lb8.43 N·m | 4.65 ft·lb6.30 N·m | 3.08 ft·lb4.17 N·m |
| 5/16" | 5/16"-24 UNF24 TPI | 10.3 kN2317 lbf | 12.0 ft·lb16.2 N·m | 8.93 ft·lb12.1 N·m | 5.90 ft·lb7.99 N·m |
| 3/8" | 3/8"-24 UNF24 TPI | 15.6 kN3504 lbf | 21.0 ft·lb28.5 N·m | 15.6 ft·lb21.1 N·m | 10.2 ft·lb13.8 N·m |
| 7/16" | 7/16"-20 UNF20 TPI | 21.1 kN4737 lbf | 32.6 ft·lb44.2 N·m | 24.3 ft·lb32.9 N·m | 15.9 ft·lb21.5 N·m |
| 1/2" | 1/2"-20 UNF20 TPI | 28.4 kN6382 lbf | 51.1 ft·lb69.2 N·m | 37.8 ft·lb51.2 N·m | 24.5 ft·lb33.2 N·m |
| 9/16" | 9/16"-18 UNF18 TPI | 36.0 kN8099 lbf | 71.9 ft·lb97.5 N·m | 53.2 ft·lb72.1 N·m | 34.4 ft·lb46.7 N·m |
| 5/8" | 5/8"-18 UNF18 TPI | 45.4 kN10213 lbf | 101.0 ft·lb137.0 N·m | 74.5 ft·lb101.0 N·m | 47.9 ft·lb65.0 N·m |
| 3/4" | 3/4"-16 UNF16 TPI | 66.2 kN14881 lbf | 175.5 ft·lb238.0 N·m | 129.2 ft·lb175.2 N·m | 82.8 ft·lb112.3 N·m |
| 7/8" | 7/8"-14 UNF14 TPI | 57.1 kN12828 lbf | 176.0 ft·lb238.6 N·m | 129.4 ft·lb175.5 N·m | 82.9 ft·lb112.4 N·m |
| 1" | 1"-12 UNF12 TPI | 74.3 kN16694 lbf | 261.5 ft·lb354.6 N·m | 192.5 ft·lb261.0 N·m | 123.5 ft·lb167.4 N·m |
| 1-1/8" | 1-1/8"-12 UNF12 TPI | 95.8 kN21546 lbf | 377.2 ft·lb511.4 N·m | 276.9 ft·lb375.4 N·m | 176.5 ft·lb239.3 N·m |
| 1-1/4" | 1-1/4"-12 UNF12 TPI | 120.2 kN27015 lbf | 522.8 ft·lb708.8 N·m | 382.8 ft·lb519.0 N·m | 242.8 ft·lb329.2 N·m |
| 1-3/8" | 1-3/8"-12 UNF12 TPI | 147.2 kN33102 lbf | 701.6 ft·lb951.2 N·m | 512.7 ft·lb695.2 N·m | 323.9 ft·lb439.1 N·m |
| 1-1/2" | 1-1/2"-12 UNF12 TPI | 177.1 kN39808 lbf | 917.1 ft·lb1243.4 N·m | 669.1 ft·lb907.2 N·m | 421.1 ft·lb571.0 N·m |
Preload is 70% of yield. Torque per ISO 16047 / VDI 2230 for standard hex heads, with the same friction μ in the threads and under the head. Click a size for wrench size, tap drill and a worked example. Always follow the manufacturer's value where one exists.
Frequently asked questions
What is the torque for a 1/4" Grade 2 bolt?
About 5.60 ft·lb (7.59 N·m) with dry threads and 4.25 ft·lb (5.76 N·m) with oiled threads (1/4"-20 UNC, 70% of yield, clamp force 5.65 kN).
What is the torque for a 3/8" Grade 2 bolt?
About 19.1 ft·lb (25.9 N·m) with dry threads and 14.4 ft·lb (19.5 N·m) with oiled threads (3/8"-16 UNC, 70% of yield, clamp force 13.8 kN).
What is the torque for a 1/2" Grade 2 bolt?
About 46.6 ft·lb (63.2 N·m) with dry threads and 35.0 ft·lb (47.5 N·m) with oiled threads (1/2"-13 UNC, 70% of yield, clamp force 25.2 kN).