Inch series · technical reference

Cup Point Socket Set Screw Dimensions

Reference geometry for inch-series hexagon socket set screws with a cup point. Cup, cone, flat and dog points are separate forms and must not be substituted from this table.

Source: ASME B18.3.

StandardASME B18.3.5D · Inch Series

RevisionSource review · 2026-09

Unitsinches

CAD ORTHOGRAPHIC REFERENCEASME B18.3.5D · INCH SERIES REFERENCE

ASME B18.3.5D cup point socket set screw dimension drawing, side view with dimension callouts, 1/4-20 UNC reference size — SIDE VIEW · LENGTH REFERENCE · 1/4-20 UNC

ASME B18.3.5D cup point socket set screw dimension drawing, end view, 1/4-20 UNC reference size — END VIEW · HEAD / DRIVE · 1/4-20 UNC

Reference size shown: 1/4-20 UNC. The drawing identifies dimension locations only. Use the table for nominal data and confirm the exact product configuration before ordering.

Cup-point set screw geometry
Nominal size	TPI	T — key engagement	C — cup Ø	J — socket size
#4	40	0.070 min	0.051 – 0.061	0.050
#6	32	0.080 min	0.064 – 0.074	0.062
#8	32	0.090 min	0.076 – 0.087	0.078
#10	24	0.100 min	0.088 – 0.102	0.094
1/4 in	20	0.125 min	0.118 – 0.132	0.125
5/16 in	18	0.156 min	0.156 – 0.172	0.156
3/8 in	16	0.188 min	0.194 – 0.212	0.188
7/16 in	14	0.219 min	0.232 – 0.252	0.219
1/2 in	13	0.250 min	0.270 – 0.291	0.250