Steel Bolt Nut Threaded Fastener Hardness Force Metric Conversion Table Standards UNC

Pre-Load and Tightening Torques of Metric Thread Steel Fasteners

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This table shows the maximum permissible tightening torques and the resulting maximum preload for coarse and fine pitch thread steel fasteners.

For guidance only

Coarse Pitch Thread
Fine Pitch Thread

Coarse Pitch Thread

Thread	Coeffecient Friction	Maximum Pre-load F ^{M max} (N)							Maximum Tightening Torque M^{A max} (Ncm)							Conversion Factor X
		Property Class to ISO898/1							Property Class to ISO898/1
		3.6	4.6	5.6 / 4.8	5.8	8.8	10.9	12.9	3.6	4.6	5.6 / 4.8	5.8	8.8	10.9	12.9
M1.6	0.100	185	200	250	333	575	810	970	4.5	5	6.5	8.5	15	21	25	0.026
	0.125	175	190	240	310	544	770	920	5	5.5	7.5	9.5	17	24	29	0.031
	0.140	165	180	230	300	530	746	895	6.5	6	8	10	18	25	30	0.034
M1.8	0.100	220	230	295	380	680	995	1150	5.5	6	8	10	18.5	26	32	0.027
	0.125	205	220	280	360	645	905	1090	6.5	7	9.5	11.5	21	30	36	0.033
	0.140	200	215	275	350	625	880	1050	7	7.5	10	12.5	13	32	38	0.036
M2.0	0.100	310	335	420	540	960	1350	1620	9.5	10.5	13.5	17	31	44	52	0.032
	0.125	295	320	400	520	910	1280	1530	11.5	12	15.5	19	35	50	60	0.039
	0.140	285	305	385	500	880	1240	1490	12	13	16.5	21.5	38	53	64	0.043
M2.5	0.100	515	560	700	910	1600	2250	2700	20	21	28	36	63	89	107	0.04
	0.125	490	530	665	860	1520	2140	2560	23	25	32	39	73	102	123	0.048
	0.140	475	510	645	830	1470	2070	2480	25	27	34	43	78	109	131	0.053
M3.0	0.100	790	855	1070	1390	2440	3430	4120	35	38	49	63	111	157	188	0.046
	0.125	770	815	1020	1320	2320	3270	3920	42	44	56	72	128	180	215	0.055
	0.140	730	785	985	1280	2250	3170	3800	44	47	60	78	137	192	230	0.061
M3.5	0.100	1050	1140	1430	1850	3270	4600	5520	54	59	75	96	171	240	290	0.052
	0.125	1000	1080	1360	1760	3120	4380	5260	63	68	86	110	196	275	330	0.063
	0.140	970	1050	1320	1710	3020	4250	5100	67	73	92	119	210	295	395	0.07
M4.0	0.100	1370	1480	1850	2400	4230	5960	7140	83	88	112	144	255	360	430	0.06
	0.125	1300	1400	1760	2280	4020	5660	6790	94	102	128	166	290	410	495	0.073
	0.140	1260	1360	1710	2220	3900	5480	6580	100	108	137	177	310	440	525	0.08
M5.0	0.100	2250	2410	3020	3920	6910	9720	11650	160	170	220	280	500	705	845	0.072
	0.125	2140	2300	2880	3740	6580	9260	11100	180	200	250	320	575	810	970	0.087
	0.140	2000	2230	2790	3620	6380	8980	10800	190	210	270	340	615	865	1040	0.096
M6	0.100	3200	3400	4270	5550	9760	13700	16450	2.8	3	3.8	4.8	8.6	12	14.5	0.00087
	0.125	3050	3240	4060	5270	9290	13050	15650	3.2	3.4	4.3	5.6	9.9	14	16.5	0.00106
	0.140	2960	1350	3940	5120	9010	12650	15200	3.5	3.7	4.6	6	10.5	15	18	0.00117
M8	0.100	5877	6260	7830	10170	17900	25200	30200	6.8	7.2	9.1	11.7	21	29	35	0.00115
	0.125	5590	5960	7460	9690	17050	24000	28800	7.9	8.3	10.5	13.6	24	34	40	0.0014
	0.140	5420	5780	7230	9390	16550	23200	27900	8.4	8.9	11	14.5	26	36	43	0.00145
M10	0.100	9350	9960	12450	16180	28500	40100	48100	13.5	14.4	18	23.4	42	58	70	0.00175
	0.125	8900	9480	11850	15400	27100	38200	45800	15.5	16.6	21	27	48	67	81	0.00195
	0.140	8640	9200	11500	14900	26300	37000	44400	17	18	22	29	51	72	87	0.00175
M12	0.100	13600	14520	18150	23500	41500	58400	70000	24	25	31	41	72	101	121	0.0021
	0.125	13000	13840	17300	22400	39600	55600	66800	27	29	36	47	83	117	140	0.0023
	0.140	12600	13400	16800	21800	38400	54000	64800	29	31	39	50	89	125	150	0.002
M14	0.100	18700	19900	24900	32300	57000	80100	96200	37	40	50	47	114	160	193	0.0024
	0.125	17800	19000	23800	30900	54300	76400	91700	43	46	58	74	132	185	220	0.0027
	0.140	17300	18400	23100	3000	52700	74100	89000	46	50	62	81	141	198	240	0.0022
M16	0.100	25700	27400	34300	44500	78300	110000	132000	57	60	76	98	174	245	295	0.0027
	0.125	24500	26100	32700	42500	74700	105000	126000	66	70	88	115	200	285	340	0.003
	0.140	23800	25300	31700	41200	72600	102000	122500	71	76	95	124	215	305	365	0.0025
M18	0.100	31300	33300	41700	54200	95300	134000	161000	79	83	105	135	240	340	405	0.003
	0.125	29800	31700	39700	51600	90900	128000	153500	91	95	121	155	275	390	470	0.0034
	0.140	28900	30800	38600	50100	88200	88200	149000	97	105	130	171	295	420	500	0.0028
M20	0.100	40200	42800	53500	69500	122500	172000	206000	111	120	148	195	340	475	570	0.0033
	0.125	38300	40800	5110	66400	117000	164000	197000	128	135	170	219	390	550	660	0.0037
	0.140	37200	39600	49600	66400	113500	159000	1915000	138	146	184	238	420	590	710	0.0033
M22	0.100	50100	53400	66800	86800	153000	215000	258000	149	160	199	260	455	640	765	0.0036
	0.125	47900	51000	63800	82900	146000	205000	246000	173	183	230	298	530	745	890	0.004
	0.140	46500	49600	62000	80600	142000	199500	239500	186	198	250	322	570	800	960	0.0033
M24	0.100	57800	61600	77100	100200	176000	248000	297000	191	203	255	330	580	820	980	0.004
	0.125	55200	58800	73600	95680	168000	236000	284000	220	235	295	382	675	950	1140	0.0044
	0.140	53600	57100	71400	92800	163500	230000	276500	235	251	315	408	725	1020	1220	0.0037
M27	0.100	76000	81200	101500	131900	323000	326000	391000	280	300	375	488	855	1210	1450	0.0045
	0.125	72600	77400	96800	125800	221000	311000	374000	325	348	435	566	995	1400	1680	0.005
	0.140	70600	75200	94100	122300	215000	302000	363000	350	376	470	610	1070	1510	1810	0.0041
M30	0.100	92500	98800	123500	160500	282000	396000	475000	380	405	510	658	1160	1640	1970	0.005
	0.125	88300	9400	117500	162700	269000	378000	454000	445	470	590	763	1350	1900	2280	0.0055
	0.140	85700	91600	114500	148800	261000	367000	441000	475	504	635	818	1450	2050	2450	0.0045
M33	0.100	115000	122800	153500	199500	351000	949000	592000	515	552	690	898	1570	2210	2650	0.0055
	0.125	110000	117200	146500	190400	335000	472000	566000	600	645	800	1045	1830	2580	3090	0.006
	0.140	107000	114000	142500	185200	326000	458000	550000	645	685	865	1110	1970	2770	3330	0.0049
M36	0.100	135000	144000	180000	234000	412000	579000	695000	665	705	885	1145	2030	2850	3420	0.006
	0.125	129000	137600	172000	223600	394000	553000	664000	775	825	1030	1340	2360	3310	3980	0.0066
	0.140	125500	134000	167500	217700	382000	538000	645000	830	885	1111	1435	2530	3560	4280	0.0053
M39	0.100	162500	173500	217000	282100	495000	696000	835000	860	920	1150	1495	2620	3680	4420	0.0053
	0.125	155000	165600	207000	269100	473000	665000	798000	1000	1075	1340	1750	3050	4290	5150	0.0065
	0.140	151000	160800	201000	261300	460000	646000	776000	1080	1155	1440	1880	3290	4620	5550	0.0072

Fine Pitch Thread

Thread	Coefficient Friction	Preload (N)			Tightening Torque (Nm)
		Property class to ISO 898/1			Property Class
		8.8	10.9	12.9	8.8	10.9	12.9
M8 x 1	0.100	19500	27500	33000	22	30	36
	0.125	18600	26200	31500	25	35	42
	0.140	18100	25500	30600	27	38	45
M10 x 1.25	0.100	30500	42900	51500	42	59	71
	0.125	29110	40900	49100	49	68	82
	0.140	28300	39800	47700	52	73	88
M12 x 1.25	0.100	46600	65500	78500	76	105	130
	0.125	44600	62500	75000	88	125	150
	0.140	43300	6100	7300	95	135	160
M14 x 1.5	0.100	63000	88500	106000	120	165	200
	0.125	60500	85000	102000	140	195	235
	0.140	58500	82500	99000	150	210	250
M16 x 1.5	0.100	85000	120000	144000	180	250	300
	0.125	81500	114000	137000	210	295	350
	0.140	79000	111000	133000	225	315	380
M18 x 1.5	0.100	111000	156000	187000	260	365	435
	0.125	106000	149000	179000	305	425	510
	0.140	103000	145000	174000	325	460	550
M20 x 1.5	0.100	140000	197000	236000	360	360	510
	0.125	134000	189000	226000	425	600	720
	0.140	130000	183000	220000	460	640	770
M22 x 1.5	0.100	172000	242000	291000	480	680	810
	0.125	165000	234000	279000	570	800	960
	0.140	161000	226000	271000	610	860	1050
M24 x 2	0.100	197000	277000	332000	610	860	1050
	0.125	188000	265000	318000	720	1000	1200
	0.140	183000	257000	30900	780	1100	1300

Pre-Load and Tightening Torques of Metric Thread Steel Fasteners

Coarse Pitch Thread

Fine Pitch Thread

Coarse Pitch Thread

Fine Pitch Thread

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