ISO 26160° flank

ISO Metric Threads

The global default for machine screws and bolts. Diameter and pitch are both in millimetres, and the designation carries the pitch whenever it is not the coarse one — M10 × 1.25 is a fine pitch, plain M10 is coarse. 82 designations are listed here, all quoted in millimetres.

Dimensions

Designation	Pitch (mm)	Major (mm)	Pitch Ø (mm)	Minor ext (mm)	Tap drill (mm)
M1 × 0.25	0.25	1	0.84	0.69	0.75
M1.2 × 0.25	0.25	1.2	1.04	0.89	0.95
M1.4 × 0.3	0.3	1.4	1.21	1.03	1.1
M1.6 × 0.35	0.35	1.6	1.37	1.17	1.25
M1.8 × 0.35	0.35	1.8	1.57	1.37	1.45
M2 × 0.4	0.4	2	1.74	1.51	1.6
M2.2 × 0.45	0.45	2.2	1.91	1.65	1.75
M2.5 × 0.45	0.45	2.5	2.21	1.95	2.05
M3 × 0.5	0.5	3	2.68	2.39	2.5
M3.5 × 0.6	0.6	3.5	3.11	2.76	2.9
M4 × 0.7	0.7	4	3.55	3.14	3.3
M4.5 × 0.75	0.75	4.5	4.01	3.58	3.75
M5 × 0.8	0.8	5	4.48	4.02	4.2
M5.5 × 0.9	0.9	5.5	4.92	4.4	4.6
M6 × 1	1	6	5.35	4.77	5
M7 × 1	1	7	6.35	5.77	6
M8 × 1.25	1.25	8	7.19	6.47	6.75
M9 × 1.25	1.25	9	8.19	7.47	7.75
M10 × 1.5	1.5	10	9.03	8.16	8.5
M11 × 1.5	1.5	11	10.03	9.16	9.5
M12 × 1.75	1.75	12	10.86	9.85	10.25
M14 × 2	2	14	12.7	11.55	12
M16 × 2	2	16	14.7	13.55	14
M18 × 2.5	2.5	18	16.38	14.93	15.5
M20 × 2.5	2.5	20	18.38	16.93	17.5
M22 × 2.5	2.5	22	20.38	18.93	19.5
M24 × 3	3	24	22.05	20.32	21
M27 × 3	3	27	25.05	23.32	24
M30 × 3.5	3.5	30	27.73	25.71	26.5
M33 × 3.5	3.5	33	30.73	28.71	29.5
M36 × 4	4	36	33.4	31.09	32
M39 × 4	4	39	36.4	34.09	35
M42 × 4.5	4.5	42	39.08	36.48	37.5
M45 × 4.5	4.5	45	42.08	39.48	40.5
M48 × 5	5	48	44.75	41.87	43
M52 × 5	5	52	48.75	45.87	47
M56 × 5.5	5.5	56	52.43	49.25	50.5
M60 × 5.5	5.5	60	56.43	53.25	54.5
M64 × 6	6	64	60.1	56.64	58
M1 × 0.2 fine	0.2	1	0.87	0.75	0.8
M1.2 × 0.2 fine	0.2	1.2	1.07	0.95	1
M1.4 × 0.2 fine	0.2	1.4	1.27	1.15	1.2
M1.6 × 0.2 fine	0.2	1.6	1.47	1.35	1.4
M1.8 × 0.2 fine	0.2	1.8	1.67	1.55	1.6
M2 × 0.25 fine	0.25	2	1.84	1.69	1.75
M2.5 × 0.35 fine	0.35	2.5	2.27	2.07	2.15
M3 × 0.35 fine	0.35	3	2.77	2.57	2.65
M3.5 × 0.35 fine	0.35	3.5	3.27	3.07	3.15
M4 × 0.5 fine	0.5	4	3.68	3.39	3.5
M4.5 × 0.5 fine	0.5	4.5	4.18	3.89	4
M5 × 0.5 fine	0.5	5	4.68	4.39	4.5
M6 × 0.75 fine	0.75	6	5.51	5.08	5.25
M7 × 0.75 fine	0.75	7	6.51	6.08	6.25
M8 × 1 fine	1	8	7.35	6.77	7
M8 × 0.75 fine	0.75	8	7.51	7.08	7.25
M9 × 1 fine	1	9	8.35	7.77	8
M10 × 1.25 fine	1.25	10	9.19	8.47	8.75
M10 × 1 fine	1	10	9.35	8.77	9
M11 × 1 fine	1	11	10.35	9.77	10
M12 × 1.5 fine	1.5	12	11.03	10.16	10.5
M12 × 1.25 fine	1.25	12	11.19	10.47	10.75
M14 × 1.5 fine	1.5	14	13.03	12.16	12.5
M16 × 1.5 fine	1.5	16	15.03	14.16	14.5
M18 × 2 fine	2	18	16.7	15.55	16
M18 × 1.5 fine	1.5	18	17.03	16.16	16.5
M20 × 2 fine	2	20	18.7	17.55	18
M20 × 1.5 fine	1.5	20	19.03	18.16	18.5
M22 × 2 fine	2	22	20.7	19.55	20
M22 × 1.5 fine	1.5	22	21.03	20.16	20.5
M24 × 2 fine	2	24	22.7	21.55	22
M27 × 2 fine	2	27	25.7	24.55	25
M30 × 2 fine	2	30	28.7	27.55	28
M33 × 3 fine	3	33	31.05	29.32	30
M36 × 3 fine	3	36	34.05	32.32	33
M39 × 3 fine	3	39	37.05	35.32	36
M42 × 3 fine	3	42	40.05	38.32	39
M45 × 3 fine	3	45	43.05	41.32	42
M48 × 3 fine	3	48	46.05	44.32	45
M52 × 4 fine	4	52	49.4	47.09	48
M56 × 4 fine	4	56	53.4	51.09	52
M60 × 4 fine	4	60	57.4	55.09	56
M64 × 4 fine	4	64	61.4	59.09	60

Other thread systems

Unified National Coarse Unified National Fine Unified National Extra Fine National Pipe Taper National Pipe Straight British Standard Pipe (parallel)British Standard Pipe (taper)Trapezoidal ACME