METRIC Thread Dimensions

37 ISO Metric screw thread designations with pitch, TPI, minor diameters and tap drill size.

Dimensions

millimetres unless stated

Designation	Pitch (mm)	Major (mm)	Minor ext (mm)	Tap drill (mm)
M1.6 × 0.35	0.35	1.6	1.17	1.25
M2 × 0.4	0.4	2	1.51	1.6
M2.5 × 0.45	0.45	2.5	1.95	2.05
M3 × 0.5	0.5	3	2.39	2.5
M3.5 × 0.6	0.6	3.5	2.76	2.9
M4 × 0.7	0.7	4	3.14	3.3
M5 × 0.8	0.8	5	4.02	4.2
M6 × 1	1	6	4.77	5
M7 × 1	1	7	5.77	6
M8 × 1.25	1.25	8	6.47	6.75
M10 × 1.5	1.5	10	8.16	8.5
M12 × 1.75	1.75	12	9.85	10.25
M14 × 2	2	14	11.55	12
M16 × 2	2	16	13.55	14
M18 × 2.5	2.5	18	14.93	15.5
M20 × 2.5	2.5	20	16.93	17.5
M22 × 2.5	2.5	22	18.93	19.5
M24 × 3	3	24	20.32	21
M27 × 3	3	27	23.32	24
M30 × 3.5	3.5	30	25.71	26.5
M33 × 3.5	3.5	33	28.71	29.5
M36 × 4	4	36	31.09	32
M42 × 4.5	4.5	42	36.48	37.5
M48 × 5	5	48	41.87	43
M56 × 5.5	5.5	56	49.25	50.5
M64 × 6	6	64	56.64	58
M8 × 1 fine	1	8	6.77	7
M10 × 1 fine	1	10	8.77	9
M10 × 1.25 fine	1.25	10	8.47	8.75
M12 × 1.25 fine	1.25	12	10.47	10.75
M12 × 1.5 fine	1.5	12	10.16	10.5
M14 × 1.5 fine	1.5	14	12.16	12.5
M16 × 1.5 fine	1.5	16	14.16	14.5
M18 × 1.5 fine	1.5	18	16.16	16.5
M20 × 1.5 fine	1.5	20	18.16	18.5
M24 × 2 fine	2	24	21.55	22
M30 × 2 fine	2	30	27.55	28