Bolt Torque Charts

Bolt tightening torque for every common thread size, grade and lubrication condition — computed, not copied from a chart.

Unified (inch)

Thread size	SAE Grade 2 lb-ft	SAE Grade 5 lb-ft	SAE Grade 8 lb-ft	18-8 Stainless lb-ft
#4-40	0.465	0.718	1.01	0.338
#6-32	0.862	1.33	1.88	0.627
#8-32	1.58	2.44	3.45	1.15
#10-24	2.29	3.54	5	1.67
#12-24	3.59	5.55	7.83	2.61
1/4-20	5.47	8.45	11.9	3.98
5/16-18	11.3	17.4	24.6	8.19
3/8-16	20	30.9	43.6	14.5
7/16-14	32	49.4	69.8	23.3
1/2-13	48.8	75.4	106	35.5
9/16-12	70.4	109	154	51.2
5/8-11	97.1	150	212	70.6
3/4-10	172	267	376	125
7/8-9	167	429	606	202
1-8	250	644	909	303
#4-48	0.509	0.786	1.11	0.37
#6-40	0.962	1.49	2.1	0.7
#8-36	1.66	2.57	3.62	1.21
#10-32	2.61	4.04	5.7	1.9
1/4-28	6.25	9.66	13.6	4.55
5/16-24	12.5	19.3	27.2	9.07
3/8-24	22.6	35	49.4	16.5
7/16-20	35.7	55.2	77.9	26
1/2-20	55	85	120	40
9/16-18	78.5	121	171	57.1
5/8-18	110	170	240	80
3/4-16	192	297	420	140
7/8-14	184	474	669	223
1-12	274	704	995	332

Metric

Thread size	Class 8.8 N·m	Class 10.9 N·m	Class 12.9 N·m	A2-70 Stainless N·m
M3	1.31	1.88	2.2	1.02
M4	3.05	4.37	5.11	2.37
M5	6.17	8.83	10.3	4.79
M6	10.5	15	17.6	8.15
M8	25.5	36.5	42.6	19.8
M10	50.5	72.2	84.4	39.1
M12	88	126	147	68.3
M14	141	201	235	109
M16	218	312	365	169
M18	312	431	504	234
M20	441	610	712	330
M22	601	831	971	451
M24	761	1050	1230	571
M27	1120	1540	1800	837
M30	1510	2090	2450	1140
M8x1.0	27.3	39	45.6	21.2
M10x1.0	56.1	80.3	93.8	43.5
M10x1.25	53.2	76.2	89	41.3
M12x1.25	96.1	138	161	74.6
M12x1.5	92	132	154	71.4
M14x1.5	152	217	254	118
M16x1.5	233	333	389	181
M18x1.5	350	485	566	263
M20x1.5	489	676	790	367
M24x2.0	830	1150	1340	623

The chart above is the dry, as-received condition (K = 0.20). Lubrication changes the answer by 25–40%: open any size for the full grade × lubrication matrix and a calculator that takes your own nut factor.

One page per size

Each size has its own page: every grade against every lubrication condition, clamp load, tensile stress area, and the formula behind it.