What are the dimensions of a DIN 7991 M6 screw?

The head is up to 12 mm across and 3.3 mm high, with a 4 mm hexagon socket. The thread is M6 × 1.

Why is the M24 head different?

DIN 7991 gives a 60° countersunk head from M22 up, instead of the 90° head of the smaller sizes, so the countersink for an M24 screw is steeper.

DIN 7991 countersunk screw dimensions, M3 to M24

DIN 7991 dimensions

DIN 7991 dimensions
Size	Pmm	dkmax, mm	kmax, mm	snom, mm	emin, mm	tmax, mm	α°
M3	0.5	6	1.7	2	2.3	1.2	90
M4	0.7	8	2.3	2.5	2.87	1.8	90
M5	0.8	10	2.8	3	3.44	2.3	90
M6	1	12	3.3	4	4.58	2.5	90
M8	1.25	16	4.4	5	5.72	3.5	90
M10	1.5	20	5.5	6	6.86	4.4	90
M12	1.75	24	6.5	8	9.15	4.6	90
M14	2	27	7	10	11.43	4.8	90
M16	2	30	7.5	10	11.43	5.3	90
M18	2.5	33	8	12	13.72	5.5	90
M20	2.5	36	8.5	12	13.72	5.9	90
M24	3	39	14	14	16	10.3	60

Dimensions in millimetres unless stated. Select a row to load its CAD files above.

DIN 7991 vs ISO 10642

DIN 7991 was withdrawn and replaced by ISO 10642, but the two heads are not the same. The DIN head is smaller and lower: at M8 it is 16 mm across and 4.4 mm high, against 17.92 mm and 4.96 mm in ISO 10642. The key is the same, 5 mm at M8. A countersink made for one does not fit the other exactly, so check which standard your supplier means before you draw the countersink.

DIN 7991 head angle and socket depth

Up to M20 the head is a 90° cone. At M24 it is a 60° cone, which makes the head much taller: 14 mm, with a socket 10.3 mm deep. The socket depth t in the table is the maximum the standard gives. The length is measured including the head, because the head ends flush with the surface.

DIN 7991 screws: common questions

What are the dimensions of a DIN 7991 M6 screw?: The head is up to 12 mm across and 3.3 mm high, with a 4 mm hexagon socket. The thread is M6 × 1.
Why is the M24 head different?: DIN 7991 gives a 60° countersunk head from M22 up, instead of the 90° head of the smaller sizes, so the countersink for an M24 screw is steeper.

Sources the dimensions were checked against (6)