M36 Bolt Torque
An M36 8.8 bolt with a coarse M36×4 thread needs about 2537.8 N·m (1871.8 ft·lb) when dry and 1883.4 N·m (1389.1 ft·lb) when oiled, tightened to 70% of yield (clamp force 365.9 kN).
| Grade | Clamp forcepreload | Dryμ 0.15 | Oiledμ 0.11 | PTFE / moly pasteμ 0.06 |
|---|---|---|---|---|
| 4.6 | 137.2 kN30846 lbf | 951.7 N·m701.9 ft·lb | 706.3 N·m520.9 ft·lb | 460.8 N·m339.9 ft·lb |
| 4.8 | 182.9 kN41128 lbf | 1268.9 N·m935.9 ft·lb | 941.7 N·m694.5 ft·lb | 614.5 N·m453.2 ft·lb |
| 5.6 | 171.5 kN38557 lbf | 1189.6 N·m877.4 ft·lb | 882.8 N·m651.1 ft·lb | 576.1 N·m424.9 ft·lb |
| 5.8 | 228.7 kN51410 lbf | 1586.1 N·m1169.9 ft·lb | 1177.1 N·m868.2 ft·lb | 768.1 N·m566.5 ft·lb |
| 6.8 | 274.4 kN61692 lbf | 1903.4 N·m1403.8 ft·lb | 1412.5 N·m1041.8 ft·lb | 921.7 N·m679.8 ft·lb |
| 8.8 | 365.9 kN82256 lbf | 2537.8 N·m1871.8 ft·lb | 1883.4 N·m1389.1 ft·lb | 1228.9 N·m906.4 ft·lb |
| 10.9 | 514.5 kN115672 lbf | 3568.8 N·m2632.2 ft·lb | 2648.5 N·m1953.4 ft·lb | 1728.2 N·m1274.6 ft·lb |
| 12.9 | 617.4 kN138806 lbf | 4282.6 N·m3158.6 ft·lb | 3178.2 N·m2344.1 ft·lb | 2073.8 N·m1529.6 ft·lb |
| A2-70 | 257.3 kN57836 lbf | 1784.4 N·m1316.1 ft·lb | 1324.2 N·m976.7 ft·lb | 864.1 N·m637.3 ft·lb |
| A4-70 | 257.3 kN57836 lbf | 1784.4 N·m1316.1 ft·lb | 1324.2 N·m976.7 ft·lb | 864.1 N·m637.3 ft·lb |
| A4-80 | 343.0 kN77115 lbf | 2379.2 N·m1754.8 ft·lb | 1765.7 N·m1302.3 ft·lb | 1152.1 N·m849.8 ft·lb |
| Grade | Clamp forcepreload | Dryμ 0.15 | Oiledμ 0.11 | PTFE / moly pasteμ 0.06 |
|---|---|---|---|---|
| 4.6 | 145.3 kN32667 lbf | 992.6 N·m732.1 ft·lb | 730.5 N·m538.8 ft·lb | 468.3 N·m345.4 ft·lb |
| 4.8 | 193.7 kN43556 lbf | 1323.5 N·m976.2 ft·lb | 973.9 N·m718.3 ft·lb | 624.4 N·m460.5 ft·lb |
| 5.6 | 181.6 kN40834 lbf | 1240.8 N·m915.2 ft·lb | 913.1 N·m673.5 ft·lb | 585.3 N·m431.7 ft·lb |
| 5.8 | 242.2 kN54445 lbf | 1654.4 N·m1220.2 ft·lb | 1217.4 N·m897.9 ft·lb | 780.5 N·m575.6 ft·lb |
| 6.8 | 290.6 kN65334 lbf | 1985.3 N·m1464.3 ft·lb | 1460.9 N·m1077.5 ft·lb | 936.5 N·m690.8 ft·lb |
| 8.8 | 387.5 kN87112 lbf | 2647.1 N·m1952.4 ft·lb | 1947.9 N·m1436.7 ft·lb | 1248.7 N·m921.0 ft·lb |
| 10.9 | 544.9 kN122501 lbf | 3722.4 N·m2745.5 ft·lb | 2739.2 N·m2020.4 ft·lb | 1756.0 N·m1295.2 ft·lb |
| 12.9 | 653.9 kN147001 lbf | 4466.9 N·m3294.6 ft·lb | 3287.1 N·m2424.4 ft·lb | 2107.2 N·m1554.2 ft·lb |
| A2-70 | 272.5 kN61250 lbf | 1861.2 N·m1372.8 ft·lb | 1369.6 N·m1010.2 ft·lb | 878.0 N·m647.6 ft·lb |
| A4-70 | 272.5 kN61250 lbf | 1861.2 N·m1372.8 ft·lb | 1369.6 N·m1010.2 ft·lb | 878.0 N·m647.6 ft·lb |
| A4-80 | 363.3 kN81667 lbf | 2481.6 N·m1830.4 ft·lb | 1826.2 N·m1346.9 ft·lb | 1170.7 N·m863.5 ft·lb |
Torque for M36 hex head bolts and nuts, standard ISO/ASME heads on steel with a 39.0 mm clearance hole. Friction μ applies to both the threads and the bearing face. Always follow the manufacturer's value where one exists.
M36 thread and dimensions
- Coarse thread
- M36×4 — pitch 4 mm
- Fine thread
- M36×3 — pitch 3 mm
- Tensile stress area Aₛ
- 816.7 mm² (coarse), 864.9 mm² (fine)
- Pitch diameter d₂
- 33.402 mm
- Tap drill
- 32 mm (coarse), 33 mm (fine)
- Wrench size (hex head)
- 55 mm
- Clearance hole
- 39.0 mm
How the M36 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 × 816.7 mm² = 365.9 kN
T = F × (0.16·P + 0.58·μ·d₂ + μ·Dₖₘ/2)
T = 365.9 kN × (0.16·4 + 0.58·0.15·33.40 + 0.15·47.00/2) mm = 2537.8 N·m
Here d₂ is the pitch diameter and Dₖₘ the effective bearing diameter of the head (47.00 mm). Change the grade, lubrication or preload in the calculator below.
Frequently asked questions
What is the torque for an M36 8.8 bolt?
About 2537.8 N·m (1871.8 ft·lb) with dry threads, 1883.4 N·m (1389.1 ft·lb) with oiled threads and 1228.9 N·m (906.4 ft·lb) with PTFE or moly paste, for a coarse M36×4 thread tightened to 70% of yield. The resulting clamp force is 365.9 kN.
What is the torque for an M36 10.9 bolt?
About 3568.8 N·m (2632.2 ft·lb) with dry threads, 2648.5 N·m (1953.4 ft·lb) with oiled threads and 1728.2 N·m (1274.6 ft·lb) with PTFE or moly paste, for a coarse M36×4 thread tightened to 70% of yield. The resulting clamp force is 514.5 kN.
What size wrench fits an M36 bolt?
A standard M36 hex head bolt or nut takes a 55 mm wrench or socket.
What drill size do I need to tap M36?
Use a 32 mm drill for M36×4 and 33 mm for M36×3.