Preload force and tightening torque for hexagon head screws (ISO 4014) for coefficients of total friction (µtot)

Coarse pitch thread, µtot = 0.10
Dimensions	Preload force (N)			Tightening torque(Nm)
	8.8	10.9	12.9	8.8	10.9	12.9
M4	4250	6200	7250	2.4	3.6	4.2
M5	6900	10200	11900	4.8	7.1	8.3
M6	9750	14300	16800	8.3	12	14
M8	17900	26300	30700	20	30	35
M10	28500	41800	48900	40	59	69
M12	41500	61000	71500	69	100	120
M14	57000	83500	98000	110	160	190
M16	78500	115000	135000	170	250	290
M18	98 000	140000	164000	245	345	405
M20	126000	180000	210000	340	490	570
M22	158000	224000	263000	460	660	770
M24	182000	259000	303000	590	840	980
M27	239000	340000	398000	870	1250	1450
M30	291000	414000	484000	1200	1700	1950

 

Fine pitch thread, µtot = 0.10
Dimensions	Preload force (N)			Tightening torque(Nm)
	8.8	10.9	12.9	8.8	10.9	12.9
M8 x 1	19600	28700	33600	22	32	37
M10 x 1.25	30600	44900	52500	42	62	72
M12 x 1.25	46600	68500	80000	75	110	130
M12 x 1.5	44000	64500	75500	72	105	125
M14 x 1.5	63000	92500	108000	120	175	200
M16 x 1.5	85500	125000	147000	180	265	310
M18 x 1.5	114000	163000	191000	270	385	450
M20 x 1.5	144000	206000	241000	375	530	620
M22 x 1.5	178000	253000	296000	500	710	830

 

Coarse pitch thread, µtot = 0.16
Dimensions	Preload force (N)			Tightening torque(Nm)
	8.8	10.9	12.9	8.8	10.9	12.9
M4	3750	5500	6450	3.2	4.7	5.5
M5	6100	9000	10500	6.4	9.3	11
M6	8650	12700	14800	11	16	19
M8	15900	23300	27300	27	39	46
M10	25300	37100	43400	53	78	91
M12	36800	54000	63500	92	135	155
M14	55500	74500	87000	145	215	250
M16	69500	102000	120000	230	335	390
M18	875000	124000	145000	325	465	540
M20	112000	160000	187000	460	660	770
M22	140000	200000	234000	620	890	1050
M24	162000	230000	269000	790	1150	1300
M27	213000	303000	355000	1150	1650	1950
M30	259000	369000	431000	1600	2250	2650

 

Fine pitch thread,   µtot = 0.16
Dimensions	Preload force (N)			Tightening torque(Nm)
	8.8	10.9	12.9	8.8	10.9	12.9
M8 x 1	17400	25600	29900	29	43	50
M10 x 1.25	27200	40000	46800	56	83	97
M12 x 1.25	41600	61000	71500	100	150	175
M12 x 1.5	39200	57500	67500	96	140	165
M16 x 1.5	56000 76000	82500 112000	96500 131000	160 245	235 360	275 425
M18 x 1.5	102000	163000	171000	370	530	620
M20 x 1.5	129000	206000	216000	520	740	860
M22 x 1.5	159000	253000	266000	690	990	1150