BS 4168-3 Hexagon Socket Set Screws with Cone Point

BS 4168-3 specifies metric hexagon socket set screws with a cone point. BSI identifies ISO 4027 as technically equivalent to the 1981 part and identical to the later 1994 edition.

Technical line drawing of a hexagon socket set screw with cone point, showing thread diameter, length, socket size and cone point.

Selected cone-point and socket dimensions

Thread d	Socket s (mm)	Cone-point diameter dt max (mm)
M3	1.5	2
M6	3	4
M10	5	7
M16	8	12
M24	12	18

Reference note: Selected values in millimetres follow the project ISO 4027 reference schedule. BSI lists ISO 4027 as technically equivalent for BS 4168-3:1981 and identical for BS 4168-3:1994. This is not the full dimension or tolerance schedule.