BS 4183 Slotted Countersunk Head Machine Screws

Nominal Size d^a	Width Across				Thickness m
	Flats s		Corners e		Thickness m
	Max.	Min.	Square	Hexagon	Max.	Min
BS 4183 - M1.6	3.2	3.02	4.5	3.7	1	0.75
BS 4183 - M2	4	3.82	5.7	4.6	1.2	0.95
BS 4183 - M2.2	4.5	4.32	6.4	5.2	1.2	0.95
BS 4183 - M2.5	5	4.82	7.1	5.8	1.6	1.35
BS 4183 - M3	5.5	5.32	7.8	6.4	1.6	1.35
BS 4183 - M3.5	6	5.82	8.5	6.9	2	1.75
BS 4183 - M4	7	6.78	9.9	8.1	2	1.75
BS 4183 - M5	8	7.78	11.3	9.2	2.5	2.25
BS 4183 - M6	10	9.78	14.1	11.5	3	2.75
BS 4183 - M8	13	12.73	18.4	15	4	3.7
BS 4183 - M10	17	16.73	24	19.6	5	4.7
BS 4183 - M8	...	...	...	13	12.73	18.4
BS 4183 - M10	...	...	...	17	16.73	24
a Nominal sizes and lengths shown in parentheses are non-preferred. All dimensions are given in millimeters. For dimensional notation, see diagram on page 1610.