ISO 4017 Hexagon head screws – Basic dimensions

Selected sizes used for CE Marking under EN 15048

Dimension (d)	M12	M16	M20	M22	M24	M27	M30	M33	M36
Thread pitch (P)	1.75	2	2.5	2.5	3	3	3.5	3.5	4
k (nom)	7.5	10	12.5	14	15	17	18.7	21	22.5
k (Grade A)	7.32-7.68	9.82-10.18	12.285-12.715	13.785-14.215	14.785-15.215	–	–	–	–
k (Grade B)	7.21-7.79	9.71-10.29	12.15-12.85	13.65-14.35	14.65-15.35	16.65-17.35	18.28-19.12	20.58-21.42	22.08-22.92
s (nom)	18	24	30	34	36	41	46	50	55
s (min, Grade A)	17.73	23.67	29.67	33.38	35.38	–	–	–	–
s (min, Grade B)	17.57	23.16	29.16	33.00	35.00	40.00	45.00	49.00	63.10
e (min, Grade A)	20.03	26.75	33.53	37.72	39.98	–	–	–	–
e (min, Grade B)	19.85	26.17	32.95	37.29	39.55	45.20	50.85	55.37	60.79

Dimensions in milimeters

Size	Grade A	Grade B
M12 (l)	Up and including 120	Including and above 125
M16 (l)	Up and including 150	Including and above 155
M20 (l)	Up and including 150	Including and above 155
M22 (l)	Up and including 150	Including and above 155
M24 (l)	Up and including 150	Including and above 155
M27 (l)	–	All lengths
M30 (l)	–	All lengths
M33 (l)	–	All lengths
M36 (l)	–	All lengths