Screw Ultimate Loads and Torques

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Ultimate Loads and Torques..

In accordance with BS EN IOS 898-1 : 1999

Use these numbers only as rough estimates for maximum values

	-	FASTENER SIZE
	-	M6	M8	M10	M12	M14	M16	M20	M22	M24	M30	M36
Pitch	mm	1.0	1.25	1.50	1.75	2.0	2.0	2.5	2.5	3.0	3.5	4.0
Stress Area	mm²	20.1	36.6	58	84.3	115	157	245	303	353	561	817

-	GRADE	-	-	-	-	-	-	-	-	-	-	-
Minimum Tensile Load (kN)	4,6	8,04	14,6	28,2	33,7	46	62,8	98	121	141	224	327
	8,8	16,1	29,2	46,4	67,4	92	125	203	252	293	466	678
	10,9	20,9	38,1	60,3	87,7	120	168	255	315	367	583	850
	12,9	24,5	44,6	70,8	103	140	192	299	370	431	684	997

Proof Loads (kN)	4,6	4,52	8,24	13	19	25,9	35,3	55,1	68,2	79,4	126	184
	8,8	11,6	21,2	33,7	48,9	66,7	91	147	182	212	337	490
	10,9	16,7	30,4	48,1	70	95,5	130	203	212	293	466	678
	12,9	19,5	35,5	56,3	81,8	112	152	238	294	342	544	792

Maximum Torque Nm	4,6	4,6104	11,2064	22,1	38,76	61,642	96,016	187,34	255,068	323,952	642,6	1126,08
	8,8	11,832	28,832	57,29	99,756	158,746	247,52	499,8	680,68	864,96	1718,7	2998,8
	10,9	17,034	41,344	81,77	142,8	227,29	353,6	690,2	792,88	1195,44	2376,6	4149,36
	12,9	19,89	48,28	95,71	166,872	266,56	413,44	809,2	1099,56	1395,36	2774,4	4847,04

Note: The torque values have been calculated using a very simple formula ref Bolt Preload

Torque = K.F_m.d

K = 0.2 is a constant from Machinery's Handbook for thread and collar friction coefficient =0,15
d = nominal diameter (m)
F _m = Maximimum Bolt tension (0,85.Proof load)

Relevant Links

Tribology -ABC..Very useful calculator for calculating the torque for any screw
Tohnichi -Screw Torque..Download with Lots of relevant information , equations and tables

Screws Index Page...

Please Send Comments to Roy Beardmore