M48 Bolt Torque
An M48 8.8 bolt with a coarse M48×5 thread needs about 6120.7 N·m (4514.4 ft·lb) when dry and 4531.9 N·m (3342.5 ft·lb) when oiled, tightened to 70% of yield (clamp force 660.0 kN).
| Grade | Clamp forcepreload | Dryμ 0.15 | Oiledμ 0.11 | PTFE / moly pasteμ 0.06 |
|---|---|---|---|---|
| 4.6 | 247.5 kN55638 lbf | 2295.3 N·m1692.9 ft·lb | 1699.5 N·m1253.5 ft·lb | 1103.6 N·m814.0 ft·lb |
| 4.8 | 330.0 kN74184 lbf | 3060.4 N·m2257.2 ft·lb | 2265.9 N·m1671.3 ft·lb | 1471.5 N·m1085.3 ft·lb |
| 5.6 | 309.4 kN69547 lbf | 2869.1 N·m2116.1 ft·lb | 2124.3 N·m1566.8 ft·lb | 1379.5 N·m1017.5 ft·lb |
| 5.8 | 412.5 kN92729 lbf | 3825.5 N·m2821.5 ft·lb | 2832.4 N·m2089.1 ft·lb | 1839.4 N·m1356.7 ft·lb |
| 6.8 | 495.0 kN111275 lbf | 4590.5 N·m3385.8 ft·lb | 3398.9 N·m2506.9 ft·lb | 2207.3 N·m1628.0 ft·lb |
| 8.8 | 660.0 kN148367 lbf | 6120.7 N·m4514.4 ft·lb | 4531.9 N·m3342.5 ft·lb | 2943.0 N·m2170.7 ft·lb |
| 10.9 | 928.1 kN208641 lbf | 8607.3 N·m6348.4 ft·lb | 6373.0 N·m4700.4 ft·lb | 4138.6 N·m3052.5 ft·lb |
| 12.9 | 1113.7 kN250370 lbf | 10328.7 N·m7618.1 ft·lb | 7647.5 N·m5640.5 ft·lb | 4966.4 N·m3663.0 ft·lb |
| Grade | Clamp forcepreload | Dryμ 0.15 | Oiledμ 0.11 | PTFE / moly pasteμ 0.06 |
|---|---|---|---|---|
| 4.6 | 269.4 kN60563 lbf | 2442.1 N·m1801.2 ft·lb | 1785.0 N·m1316.6 ft·lb | 1128.0 N·m832.0 ft·lb |
| 4.8 | 359.2 kN80751 lbf | 3256.1 N·m2401.6 ft·lb | 2380.0 N·m1755.4 ft·lb | 1504.0 N·m1109.3 ft·lb |
| 5.6 | 336.7 kN75704 lbf | 3052.6 N·m2251.5 ft·lb | 2231.3 N·m1645.7 ft·lb | 1410.0 N·m1040.0 ft·lb |
| 5.8 | 449.0 kN100939 lbf | 4070.1 N·m3002.0 ft·lb | 2975.1 N·m2194.3 ft·lb | 1880.0 N·m1386.6 ft·lb |
| 6.8 | 538.8 kN121126 lbf | 4884.1 N·m3602.4 ft·lb | 3570.1 N·m2633.2 ft·lb | 2256.0 N·m1663.9 ft·lb |
| 8.8 | 718.4 kN161502 lbf | 6512.2 N·m4803.1 ft·lb | 4760.1 N·m3510.9 ft·lb | 3008.0 N·m2218.6 ft·lb |
| 10.9 | 1010.2 kN227112 lbf | 9157.8 N·m6754.4 ft·lb | 6693.9 N·m4937.2 ft·lb | 4230.0 N·m3119.9 ft·lb |
| 12.9 | 1212.3 kN272535 lbf | 10989.3 N·m8105.3 ft·lb | 8032.7 N·m5924.6 ft·lb | 5076.0 N·m3743.9 ft·lb |
Torque for M48 hex head bolts and nuts, standard ISO/ASME heads on steel with a 52.0 mm clearance hole. Friction μ applies to both the threads and the bearing face. Always follow the manufacturer's value where one exists.
M48 thread and dimensions
- Coarse thread
- M48×5 — pitch 5 mm
- Fine thread
- M48×3 — pitch 3 mm
- Tensile stress area Aₛ
- 1473.1 mm² (coarse), 1603.6 mm² (fine)
- Pitch diameter d₂
- 44.752 mm
- Tap drill
- 43 mm (coarse), 45 mm (fine)
- Wrench size (hex head)
- 75 mm
- Clearance hole
- 52.0 mm
How the M48 torque is calculated
Preload is 70% of the bolt's yield strength times its tensile stress area. Torque then follows the ISO 16047 / VDI 2230 formula, which splits it into thread pitch, thread friction and friction under the head:
F = 70% × 640 MPa × 1473.1 mm² = 660.0 kN
T = F × (0.16·P + 0.58·μ·d₂ + μ·Dₖₘ/2)
T = 660.0 kN × (0.16·5 + 0.58·0.15·44.75 + 0.15·63.50/2) mm = 6120.7 N·m
Here d₂ is the pitch diameter and Dₖₘ the effective bearing diameter of the head (63.50 mm). Change the grade, lubrication or preload in the calculator below.
Frequently asked questions
What is the torque for an M48 8.8 bolt?
About 6120.7 N·m (4514.4 ft·lb) with dry threads, 4531.9 N·m (3342.5 ft·lb) with oiled threads and 2943.0 N·m (2170.7 ft·lb) with PTFE or moly paste, for a coarse M48×5 thread tightened to 70% of yield. The resulting clamp force is 660.0 kN.
What is the torque for an M48 10.9 bolt?
About 8607.3 N·m (6348.4 ft·lb) with dry threads, 6373.0 N·m (4700.4 ft·lb) with oiled threads and 4138.6 N·m (3052.5 ft·lb) with PTFE or moly paste, for a coarse M48×5 thread tightened to 70% of yield. The resulting clamp force is 928.1 kN.
What size wrench fits an M48 bolt?
A standard M48 hex head bolt or nut takes a 75 mm wrench or socket.
What drill size do I need to tap M48?
Use a 43 mm drill for M48×5 and 45 mm for M48×3.