De module m for spur gears (NEN 1630, DIN 780, ISO54) in two series, series 1 is preferred.
series 1	0.1	0.12	0.16	0.20	0.25	0.3	0.4	0.5	0.6	0.7	0.8
	0.9	1	1.25	1.5	2	2.5	3	4	5	6	8
	10	12	16	20	25	32	40	50	60
series 2	0.11	0.14	0.18	0.22	0.28	0.35	0.45	0.55	0.65	0.75	0.85
	0.95	1.125	1.375	1.75	2.25	2.75	3.5	4.5	5.5	7	9
	11	14	18	22	28	36	45	55	70