ISO

Compared to standard threads, a fine thread has a smaller pitch which increases the resilience. It is used e.g. for adjusting screws in measuring instruments because it allows for finer settings. The term consists of the letter M, the nominal diameter and the pitch, the flank angle is 60°.

Specifications of International Thread Standards
Nom. Dia. (mm)	Pitch (mm)	Tap Drill (mm)
M 1.0	0.20	0.78
M 1.1	0.20	0.88
M 1.2	0.20	0.98
M 1.4	0.20	1.18
M 1.4	0.25	1.30
M 1.6	0.20	1.38
M 1.6	0.25	1.33
M 1.8	0.20	1.58
M 1.8	0.25	1.53
M 2.0	0.20	1.78
M 2.0	0.25	1.73
M 2.0	0.35	1.62
M 2.2	0.20	1.98
M 2.2	0.25	1.93
M 2.2	0.35	1.82
M 2.5	0.20	2.28
M 2.5	0.25	2.23
M 2.5	0.35	2.12
M 3.0	0.20	2.78
M 3.0	0.25	2.73
M 3.0	0.35	2.62
M 3.5	0.20	3.28
M 3.5	0.25	3.23
M 3.5	0.35	3.12
M 4.0	0.20	3.78
M 4.0	0.25	3.73
M 4.0	0.35	3.62
M 4.5	0.20	4.28
M 4.5	0.25	4.23
M 4.5	0.35	4.12
M 5.0	0.20	4.78
M 5.0	0.25	4.73
M 5.0	0.35	4.62
M 5.5	0.20	5.28
M 5.5	0.25	5.23
M 5.5	0.35	5.12
M 6.0	0.20	5.78
M 6.0	0.25	5.73
M 6.0	0.35	5.62
M 6.5	0.20	6.28
M 6.5	0.25	6.23
M 6.5	0.35	6.12
M 7.0	0.20	6.78
M 7.0	0.25	6.73
M 7.0	0.35	6.62
M 7.5	0.20	7.28
M 7.5	0.25	7.23
M 7.5	0.35	7.12
M 8.0	0.20	7.78
M 8.0	0.25	7.73
M 8.0	0.35	7.62
M 8.5	0.20	8.28
M 8.5	0.25	8.23
M 8.5	0.35	8.12
M 9.0	0.20	8.78
M 9.0	0.25	8.73
M 9.0	0.35	8.62
M 9.5	0.20	9.28
M 9.5	0.25	9.23
M 9.5	0.35	9.12
M 10.0	0.20	9.78
M 10.0	0.25	9.73
M 10.0	0.35	9.62
M 10.5	0.35	10.12
M 11.0	0.35	10.62
M 11.5	0.35	11.12
M 12.0	0.35	11.62
M 12.5	0.35	12.12
M 13.0	0.35	12.62
M 13.5	0.35	13.12
M 14.0	0.35	13.62
M 14.5	0.35	14.12
M 15.0	0.35	14.62
M 15.5	0.35	15.12
M 16.0	0.35	15.62
M 17.0	0.35	16.62
M 18.0	0.35	17.62
M 19.0	0.35	18.62
M 20.0	0.35	19.62
M 21.0	0.35	20.62
M 22.0	0.35	21.62
M 23.0	0.35	22.62
M 24.0	0.35	23.62
M 25.0	0.35	24.62
M 26.0	0.35	25.62
M 27.0	0.35	26.62
M 28.0	0.35	27.62
M 29.0	0.35	28.62
M 30.0	0.35	29.62
M 31.0	0.35	30.62
M 32.0	0.35	31.62
M 33.0	0.35	32.62
M 34.0	0.35	33.62
M 35.0	0.35	34.62
M 36.0	0.35	35.62
M 37.0	0.35	36.62
M 38.0	0.35	37.62
M 39.0	0.35	38.62
M 40.0	0.35	39.62
M 42.0	0.35	41.62
M 45.0	0.35	44.62
M 48.0	0.35	47.62
M 50.0	0.35	49.62

See Other ISO threads

This thread is a globally standardized thread, it replaces older metric thread and most threads with inch dimensions. The label consists of the letter M followed by a number indicating the nominal diameter, the flank angle is 60 °.

Specifications of International Thread Standards
Nom. Dia. (mm)	Pitch (mm)	Tap Drill (mm)
M 1.0	0.25	0.78
M 1.1	0.25	0.83
M 1.2	0.25	0.93
M 1.4	0.30	1.08
M 1.6	0.35	1.22
M 1.8	0.35	1.42
M 2.0	0.40	1.57
M 2.2	0.45	1.71
M 2.5	0.45	2.01
M 3.0	0.50	2.46
M 3.5	0.60	2.85
M 4.0	0.70	3.24
M 4.5	0.75	3.69
M 5.0	0.80	4.13
M 6.0	1.00	4.92
M 7.0	1.00	5.92
M 8.0	1.25	6.65
M 9.0	1.25	7.65
M 10.0	1.50	8.38
M 11.0	1.50	9.38
M 12.0	1.75	10.11
M 14.0	2.00	11.84
M 16.0	2.00	13.84
M 18.0	2.50	15.29
M 20.0	2.50	17.29
M 22.0	2.50	19.29
M 24.0	3.00	20.75
M 27.0	3.00	23.75
M 30.0	3.50	26.21
M 33.0	3.50	29.21
M 36.0	4.00	31.67
M 39.0	4.00	34.67
M 42.0	4.50	37.13
M 45.0	4.50	40.13
M 48.0	5.00	42.59
M 52.0	5.00	46.59
M 56.0	5.50	50.05
M 60.0	5.50	54.05
M 64.0	6.00	57.51
M 68.0	6.00	61.51

See Other ISO threads

ISO Metric Fine Thread I

ISO Metric Coarse Thread