A4-80 Stainless Steel Bolt Torque Chart

Tightening torque and clamp force for A4-80 stainless bolts from M1.6 to M39. For example, an M8 A4-80 bolt needs about 24.9 N·m (18.4 ft·lb) with dry threads.

High-strength acid-resistant stainless steel (316). Stainless threads gall easily: always lubricate and tighten slowly.

Standard: Stainless steel (ISO 3506-1)
Yield strength used: 600 MPa (87 ksi)
Tensile strength: 800 MPa (116 ksi)
Sizes covered: M1.6 – M39

A4-80 stainless — 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	0.53 kN120 lbf	0.19 N·m0.14 ft·lb	0.14 N·m0.11 ft·lb	0.10 N·m0.07 ft·lb
M2	M2×0.40.4 mm	0.87 kN196 lbf	0.39 N·m0.29 ft·lb	0.29 N·m0.22 ft·lb	0.20 N·m0.15 ft·lb
M2.5	M2.5×0.450.45 mm	1.42 kN320 lbf	0.78 N·m0.58 ft·lb	0.59 N·m0.44 ft·lb	0.40 N·m0.29 ft·lb
M3	M3×0.50.5 mm	2.11 kN475 lbf	1.34 N·m0.99 ft·lb	1.01 N·m0.74 ft·lb	0.68 N·m0.50 ft·lb
M3.5	M3.5×0.60.6 mm	2.85 kN640 lbf	2.06 N·m1.52 ft·lb	1.55 N·m1.15 ft·lb	1.05 N·m0.77 ft·lb
M4	M4×0.70.7 mm	3.69 kN829 lbf	3.08 N·m2.27 ft·lb	2.32 N·m1.71 ft·lb	1.57 N·m1.15 ft·lb
M5	M5×0.80.8 mm	5.96 kN1339 lbf	5.99 N·m4.42 ft·lb	4.50 N·m3.32 ft·lb	3.02 N·m2.23 ft·lb
M6	M6×11 mm	8.45 kN1900 lbf	10.4 N·m7.64 ft·lb	7.80 N·m5.75 ft·lb	5.24 N·m3.86 ft·lb
M7	M7×11 mm	12.1 kN2725 lbf	16.8 N·m12.4 ft·lb	12.6 N·m9.26 ft·lb	8.34 N·m6.15 ft·lb
M8	M8×1.251.25 mm	15.4 kN3457 lbf	24.9 N·m18.4 ft·lb	18.7 N·m13.8 ft·lb	12.5 N·m9.22 ft·lb
M10	M10×1.51.5 mm	24.4 kN5475 lbf	48.7 N·m35.9 ft·lb	36.5 N·m26.9 ft·lb	24.4 N·m18.0 ft·lb
M12	M12×1.751.75 mm	35.4 kN7956 lbf	83.6 N·m61.6 ft·lb	62.7 N·m46.2 ft·lb	41.7 N·m30.8 ft·lb
M14	M14×22 mm	48.5 kN10900 lbf	132.9 N·m98.0 ft·lb	99.6 N·m73.4 ft·lb	66.2 N·m48.8 ft·lb
M16	M16×22 mm	65.8 kN14793 lbf	203.7 N·m150.2 ft·lb	151.8 N·m112.0 ft·lb	99.9 N·m73.7 ft·lb
M18	M18×2.52.5 mm	80.8 kN18173 lbf	284.6 N·m209.9 ft·lb	212.9 N·m157.0 ft·lb	141.3 N·m104.2 ft·lb
M20	M20×2.52.5 mm	102.8 kN23113 lbf	398.3 N·m293.8 ft·lb	296.8 N·m218.9 ft·lb	195.4 N·m144.1 ft·lb
M22	M22×2.52.5 mm	127.4 kN28647 lbf	543.5 N·m400.8 ft·lb	403.5 N·m297.6 ft·lb	263.6 N·m194.4 ft·lb
M24	M24×33 mm	148.1 kN33283 lbf	686.1 N·m506.1 ft·lb	511.4 N·m377.2 ft·lb	336.7 N·m248.3 ft·lb
M27	M27×33 mm	193.0 kN43377 lbf	1007.3 N·m742.9 ft·lb	747.4 N·m551.3 ft·lb	487.6 N·m359.6 ft·lb
M30	M30×3.53.5 mm	235.4 kN52930 lbf	1370.7 N·m1011.0 ft·lb	1018.8 N·m751.4 ft·lb	666.8 N·m491.8 ft·lb
M33	M33×3.53.5 mm	291.3 kN65485 lbf	1845.2 N·m1360.9 ft·lb	1367.3 N·m1008.5 ft·lb	889.5 N·m656.0 ft·lb
M36	M36×44 mm	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
M39	M39×44 mm	409.8 kN92130 lbf	3067.5 N·m2262.5 ft·lb	2270.6 N·m1674.7 ft·lb	1473.6 N·m1086.9 ft·lb

A4-80 stainless — 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	0.66 kN148 lbf	0.22 N·m0.17 ft·lb	0.17 N·m0.12 ft·lb	0.11 N·m0.08 ft·lb
M2	M2×0.250.25 mm	1.03 kN231 lbf	0.44 N·m0.33 ft·lb	0.33 N·m0.24 ft·lb	0.21 N·m0.16 ft·lb
M2.5	M2.5×0.350.35 mm	1.56 kN350 lbf	0.84 N·m0.62 ft·lb	0.63 N·m0.46 ft·lb	0.41 N·m0.30 ft·lb
M3	M3×0.350.35 mm	2.35 kN529 lbf	1.46 N·m1.07 ft·lb	1.08 N·m0.80 ft·lb	0.70 N·m0.52 ft·lb
M3.5	M3.5×0.350.35 mm	3.32 kN746 lbf	2.32 N·m1.71 ft·lb	1.71 N·m1.26 ft·lb	1.11 N·m0.82 ft·lb
M4	M4×0.50.5 mm	4.11 kN925 lbf	3.35 N·m2.47 ft·lb	2.49 N·m1.84 ft·lb	1.63 N·m1.21 ft·lb
M5	M5×0.50.5 mm	6.77 kN1522 lbf	6.59 N·m4.86 ft·lb	4.88 N·m3.60 ft·lb	3.16 N·m2.33 ft·lb
M6	M6×0.750.75 mm	9.25 kN2080 lbf	11.1 N·m8.18 ft·lb	8.26 N·m6.09 ft·lb	5.42 N·m4.00 ft·lb
M7	M7×0.750.75 mm	13.1 kN2940 lbf	17.8 N·m13.1 ft·lb	13.2 N·m9.70 ft·lb	8.56 N·m6.31 ft·lb
M8	M8×11 mm	16.5 kN3698 lbf	26.2 N·m19.3 ft·lb	19.5 N·m14.4 ft·lb	12.8 N·m9.45 ft·lb
M10	M10×1.251.25 mm	25.7 kN5778 lbf	50.7 N·m37.4 ft·lb	37.8 N·m27.9 ft·lb	24.8 N·m18.3 ft·lb
M12	M12×1.51.5 mm	37.0 kN8321 lbf	86.4 N·m63.8 ft·lb	64.4 N·m47.5 ft·lb	42.4 N·m31.3 ft·lb
M14	M14×1.51.5 mm	52.3 kN11760 lbf	140.7 N·m103.8 ft·lb	104.3 N·m76.9 ft·lb	67.9 N·m50.1 ft·lb
M16	M16×1.51.5 mm	70.2 kN15792 lbf	213.8 N·m157.7 ft·lb	157.8 N·m116.4 ft·lb	101.9 N·m75.2 ft·lb
M18	M18×1.51.5 mm	90.8 kN20417 lbf	310.2 N·m228.8 ft·lb	228.3 N·m168.4 ft·lb	146.3 N·m107.9 ft·lb
M20	M20×1.51.5 mm	114.0 kN25635 lbf	429.8 N·m317.0 ft·lb	315.5 N·m232.7 ft·lb	201.2 N·m148.4 ft·lb
M22	M22×1.51.5 mm	139.9 kN31447 lbf	581.9 N·m429.2 ft·lb	426.2 N·m314.3 ft·lb	270.4 N·m199.4 ft·lb
M24	M24×22 mm	161.5 kN36296 lbf	731.3 N·m539.4 ft·lb	538.3 N·m397.0 ft·lb	345.2 N·m254.6 ft·lb
M27	M27×22 mm	208.2 kN46808 lbf	1065.1 N·m785.6 ft·lb	781.5 N·m576.4 ft·lb	497.8 N·m367.2 ft·lb
M30	M30×22 mm	260.9 kN58654 lbf	1478.0 N·m1090.1 ft·lb	1081.8 N·m797.9 ft·lb	685.7 N·m505.7 ft·lb
M33	M33×22 mm	319.5 kN71834 lbf	1973.9 N·m1455.9 ft·lb	1442.2 N·m1063.7 ft·lb	910.5 N·m671.5 ft·lb
M36	M36×33 mm	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
M39	M39×33 mm	431.9 kN97100 lbf	3187.8 N·m2351.2 ft·lb	2341.1 N·m1726.7 ft·lb	1494.4 N·m1102.2 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 A4-80 bolt?

About 24.9 N·m (18.4 ft·lb) with dry threads and 18.7 N·m (13.8 ft·lb) with oiled threads (M8×1.25, 70% of yield, clamp force 15.4 kN).

What is the torque for an M10 A4-80 bolt?

About 48.7 N·m (35.9 ft·lb) with dry threads and 36.5 N·m (26.9 ft·lb) with oiled threads (M10×1.5, 70% of yield, clamp force 24.4 kN).

What is the torque for an M12 A4-80 bolt?

About 83.6 N·m (61.6 ft·lb) with dry threads and 62.7 N·m (46.2 ft·lb) with oiled threads (M12×1.75, 70% of yield, clamp force 35.4 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