BS 768 Slotted Grub Screws

BS 768:1958 specifies slotted grub screws, including different thread systems and point forms. The schematic shows a flat-point form; the schedule below is a selected BSW thread reference.

Schematic side view of a slotted flat-point grub screw with nominal diameter and length dimensions

Selected BSW thread reference dimensions

Nominal BSW size (in.)Major diameter (in.)Threads per inch
1/80.125040
3/160.187524
1/40.250020
5/160.312518
3/80.375016
1/20.500012

Note: This is a thread-series reference, not the complete BS 768 grub-screw dimensional schedule. BS 768 also includes UNC, UNF, BA and BSF threads, and multiple point forms; screw length, slot and point dimensions depend on the selected type and size.