12.9 Bolt Torque Chart

Tightening torque and clamp force for Class 12.9 bolts from M1.6 to M64. For example, an M8 12.9 bolt needs about 44.8 N·m (33.1 ft·lb) with dry threads.

Highest standard ISO class, typically socket head cap screws. Very strong but less ductile and sensitive to hydrogen embrittlement.

Standard: Metric (ISO 898-1)
Yield strength used: 1080 MPa (157 ksi)
Tensile strength: 1200 MPa (174 ksi)
Sizes covered: M1.6 – M64

Class 12.9 — Coarse thread, tightening torque at 70% of yield
Size	Threadpitch	Clamp forcepreload	Dryμ 0.15	Oiledμ 0.11	PTFE / moly pasteμ 0.06
M1.6	M1.6×0.350.35 mm	0.96 kN216 lbf	0.34 N·m0.25 ft·lb	0.26 N·m0.19 ft·lb	0.18 N·m0.13 ft·lb
M2	M2×0.40.4 mm	1.57 kN352 lbf	0.70 N·m0.52 ft·lb	0.53 N·m0.39 ft·lb	0.36 N·m0.27 ft·lb
M2.5	M2.5×0.450.45 mm	2.56 kN576 lbf	1.41 N·m1.04 ft·lb	1.06 N·m0.78 ft·lb	0.71 N·m0.53 ft·lb
M3	M3×0.50.5 mm	3.80 kN855 lbf	2.41 N·m1.78 ft·lb	1.81 N·m1.34 ft·lb	1.22 N·m0.90 ft·lb
M3.5	M3.5×0.60.6 mm	5.12 kN1151 lbf	3.71 N·m2.74 ft·lb	2.80 N·m2.06 ft·lb	1.88 N·m1.39 ft·lb
M4	M4×0.70.7 mm	6.64 kN1492 lbf	5.55 N·m4.09 ft·lb	4.18 N·m3.09 ft·lb	2.82 N·m2.08 ft·lb
M5	M5×0.80.8 mm	10.7 kN2410 lbf	10.8 N·m7.95 ft·lb	8.11 N·m5.98 ft·lb	5.43 N·m4.01 ft·lb
M6	M6×11 mm	15.2 kN3420 lbf	18.6 N·m13.7 ft·lb	14.0 N·m10.4 ft·lb	9.43 N·m6.96 ft·lb
M7	M7×11 mm	21.8 kN4905 lbf	30.2 N·m22.3 ft·lb	22.6 N·m16.7 ft·lb	15.0 N·m11.1 ft·lb
M8	M8×1.251.25 mm	27.7 kN6222 lbf	44.8 N·m33.1 ft·lb	33.7 N·m24.8 ft·lb	22.5 N·m16.6 ft·lb
M10	M10×1.51.5 mm	43.8 kN9856 lbf	87.7 N·m64.7 ft·lb	65.8 N·m48.5 ft·lb	43.8 N·m32.3 ft·lb
M12	M12×1.751.75 mm	63.7 kN14322 lbf	150.5 N·m111.0 ft·lb	112.8 N·m83.2 ft·lb	75.1 N·m55.4 ft·lb
M14	M14×22 mm	87.3 kN19620 lbf	239.3 N·m176.5 ft·lb	179.2 N·m132.2 ft·lb	119.2 N·m87.9 ft·lb
M16	M16×22 mm	118.4 kN26627 lbf	366.7 N·m270.4 ft·lb	273.3 N·m201.5 ft·lb	179.9 N·m132.7 ft·lb
M18	M18×2.52.5 mm	145.5 kN32712 lbf	512.2 N·m377.8 ft·lb	383.3 N·m282.7 ft·lb	254.3 N·m187.5 ft·lb
M20	M20×2.52.5 mm	185.1 kN41604 lbf	717.0 N·m528.8 ft·lb	534.3 N·m394.1 ft·lb	351.7 N·m259.4 ft·lb
M22	M22×2.52.5 mm	229.4 kN51564 lbf	978.2 N·m721.5 ft·lb	726.4 N·m535.8 ft·lb	474.5 N·m350.0 ft·lb
M24	M24×33 mm	266.5 kN59910 lbf	1235.0 N·m910.9 ft·lb	920.5 N·m678.9 ft·lb	606.0 N·m447.0 ft·lb
M27	M27×33 mm	347.3 kN78079 lbf	1813.1 N·m1337.3 ft·lb	1345.4 N·m992.3 ft·lb	877.6 N·m647.3 ft·lb
M30	M30×3.53.5 mm	423.8 kN95275 lbf	2467.3 N·m1819.8 ft·lb	1833.8 N·m1352.6 ft·lb	1200.3 N·m885.3 ft·lb
M33	M33×3.53.5 mm	524.3 kN117873 lbf	3321.3 N·m2449.7 ft·lb	2461.2 N·m1815.3 ft·lb	1601.0 N·m1180.9 ft·lb
M36	M36×44 mm	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
M39	M39×44 mm	737.7 kN165834 lbf	5521.6 N·m4072.5 ft·lb	4087.1 N·m3014.5 ft·lb	2652.6 N·m1956.4 ft·lb
M42	M42×4.54.5 mm	847.4 kN190505 lbf	6852.8 N·m5054.3 ft·lb	5079.3 N·m3746.3 ft·lb	3305.8 N·m2438.2 ft·lb
M45	M45×4.54.5 mm	987.3 kN221962 lbf	8526.6 N·m6288.9 ft·lb	6306.2 N·m4651.2 ft·lb	4085.9 N·m3013.6 ft·lb
M48	M48×55 mm	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
M52	M52×55 mm	1328.9 kN298753 lbf	13216.6 N·m9748.1 ft·lb	9763.9 N·m7201.5 ft·lb	6311.2 N·m4654.9 ft·lb
M56	M56×5.55.5 mm	1534.7 kN345012 lbf	16486.0 N·m12159.5 ft·lb	12186.2 N·m8988.1 ft·lb	7886.3 N·m5816.6 ft·lb
M60	M60×5.55.5 mm	1785.7 kN401438 lbf	20380.6 N·m15032.0 ft·lb	15037.1 N·m11090.8 ft·lb	9693.6 N·m7149.6 ft·lb
M64	M64×66 mm	2023.0 kN454796 lbf	24553.1 N·m18109.5 ft·lb	18129.5 N·m13371.7 ft·lb	11706.0 N·m8633.9 ft·lb

Class 12.9 — Fine thread, tightening torque at 70% of yield
Size	Threadpitch	Clamp forcepreload	Dryμ 0.15	Oiledμ 0.11	PTFE / moly pasteμ 0.06
M1.6	M1.6×0.20.2 mm	1.18 kN266 lbf	0.40 N·m0.30 ft·lb	0.30 N·m0.22 ft·lb	0.20 N·m0.14 ft·lb
M2	M2×0.250.25 mm	1.85 kN416 lbf	0.80 N·m0.59 ft·lb	0.59 N·m0.44 ft·lb	0.39 N·m0.29 ft·lb
M2.5	M2.5×0.350.35 mm	2.80 kN630 lbf	1.51 N·m1.11 ft·lb	1.13 N·m0.83 ft·lb	0.74 N·m0.55 ft·lb
M3	M3×0.350.35 mm	4.24 kN953 lbf	2.62 N·m1.93 ft·lb	1.95 N·m1.43 ft·lb	1.27 N·m0.93 ft·lb
M3.5	M3.5×0.350.35 mm	5.97 kN1343 lbf	4.17 N·m3.08 ft·lb	3.08 N·m2.27 ft·lb	1.99 N·m1.47 ft·lb
M4	M4×0.50.5 mm	7.40 kN1664 lbf	6.03 N·m4.45 ft·lb	4.49 N·m3.31 ft·lb	2.94 N·m2.17 ft·lb
M5	M5×0.50.5 mm	12.2 kN2740 lbf	11.9 N·m8.76 ft·lb	8.78 N·m6.47 ft·lb	5.68 N·m4.19 ft·lb
M6	M6×0.750.75 mm	16.7 kN3744 lbf	20.0 N·m14.7 ft·lb	14.9 N·m11.0 ft·lb	9.76 N·m7.20 ft·lb
M7	M7×0.750.75 mm	23.5 kN5292 lbf	32.0 N·m23.6 ft·lb	23.7 N·m17.5 ft·lb	15.4 N·m11.4 ft·lb
M8	M8×11 mm	29.6 kN6657 lbf	47.2 N·m34.8 ft·lb	35.1 N·m25.9 ft·lb	23.1 N·m17.0 ft·lb
M10	M10×1.251.25 mm	46.3 kN10401 lbf	91.3 N·m67.4 ft·lb	68.0 N·m50.2 ft·lb	44.7 N·m33.0 ft·lb
M12	M12×1.51.5 mm	66.6 kN14977 lbf	155.6 N·m114.8 ft·lb	115.9 N·m85.5 ft·lb	76.3 N·m56.3 ft·lb
M14	M14×1.51.5 mm	94.2 kN21167 lbf	253.2 N·m186.8 ft·lb	187.7 N·m138.4 ft·lb	122.2 N·m90.1 ft·lb
M16	M16×1.51.5 mm	126.4 kN28425 lbf	384.8 N·m283.8 ft·lb	284.1 N·m209.5 ft·lb	183.4 N·m135.3 ft·lb
M18	M18×1.51.5 mm	163.5 kN36750 lbf	558.4 N·m411.8 ft·lb	410.9 N·m303.1 ft·lb	263.4 N·m194.3 ft·lb
M20	M20×1.51.5 mm	205.3 kN46143 lbf	773.7 N·m570.7 ft·lb	567.9 N·m418.9 ft·lb	362.1 N·m267.1 ft·lb
M22	M22×1.51.5 mm	251.8 kN56605 lbf	1047.5 N·m772.6 ft·lb	767.1 N·m565.8 ft·lb	486.7 N·m358.9 ft·lb
M24	M24×22 mm	290.6 kN65334 lbf	1316.4 N·m970.9 ft·lb	968.9 N·m714.6 ft·lb	621.3 N·m458.2 ft·lb
M27	M27×22 mm	374.8 kN84254 lbf	1917.2 N·m1414.1 ft·lb	1406.6 N·m1037.5 ft·lb	896.0 N·m660.9 ft·lb
M30	M30×22 mm	469.6 kN105576 lbf	2660.4 N·m1962.2 ft·lb	1947.3 N·m1436.2 ft·lb	1234.2 N·m910.3 ft·lb
M33	M33×22 mm	575.2 kN129302 lbf	3553.0 N·m2620.6 ft·lb	2595.9 N·m1914.7 ft·lb	1638.8 N·m1208.7 ft·lb
M36	M36×33 mm	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
M39	M39×33 mm	777.5 kN174780 lbf	5738.1 N·m4232.2 ft·lb	4213.9 N·m3108.0 ft·lb	2689.8 N·m1983.9 ft·lb
M42	M42×33 mm	911.7 kN204962 lbf	7229.7 N·m5332.3 ft·lb	5300.1 N·m3909.2 ft·lb	3370.6 N·m2486.0 ft·lb
M45	M45×33 mm	1056.7 kN237547 lbf	8959.4 N·m6608.1 ft·lb	6558.2 N·m4837.1 ft·lb	4157.0 N·m3066.1 ft·lb
M48	M48×33 mm	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
M52	M52×44 mm	1382.2 kN310720 lbf	13601.3 N·m10031.8 ft·lb	9988.6 N·m7367.2 ft·lb	6375.9 N·m4702.6 ft·lb
M56	M56×44 mm	1620.8 kN364377 lbf	17156.8 N·m12654.2 ft·lb	12577.4 N·m9276.6 ft·lb	7998.0 N·m5899.0 ft·lb
M60	M60×44 mm	1878.5 kN422306 lbf	21145.1 N·m15595.8 ft·lb	15479.5 N·m11417.1 ft·lb	9813.9 N·m7238.4 ft·lb
M64	M64×44 mm	2155.2 kN484506 lbf	25705.9 N·m18959.7 ft·lb	18794.9 N·m13862.4 ft·lb	11884.0 N·m8765.2 ft·lb

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 an M8 12.9 bolt?

About 44.8 N·m (33.1 ft·lb) with dry threads and 33.7 N·m (24.8 ft·lb) with oiled threads (M8×1.25, 70% of yield, clamp force 27.7 kN).

What is the torque for an M10 12.9 bolt?

About 87.7 N·m (64.7 ft·lb) with dry threads and 65.8 N·m (48.5 ft·lb) with oiled threads (M10×1.5, 70% of yield, clamp force 43.8 kN).

What is the torque for an M12 12.9 bolt?

About 150.5 N·m (111.0 ft·lb) with dry threads and 112.8 N·m (83.2 ft·lb) with oiled threads (M12×1.75, 70% of yield, clamp force 63.7 kN).

Other grades

4.6 4.8 5.6 5.8 6.8 8.8 9.8 10.9 12.9 Grade 2 Grade 5 Grade 8 A307 A325 A490 A574 A2-70 A4-70 A4-80