Self-tapping Screw, #4 x 0.25"

Self-tapping screws: #4 x 1/4″ (6.4mm) pan head.

Part numberDatasheet
Digi-Key: HM1441-NDHammond 1593ATS100
Farnell: 1876931Hammond 1593ATS100
Mouser: 546-1593ATS100Hammond 1593ATS100
RS: 570-691Hammond 1593ATS100

These are used to mount the PCB in SC131 Pocket Sized RomWBW CP/M Computer.

A cheaper alternative, is to buy a generic version, such as these:

Part numberDatasheet
Digi-Key: ??
Farnell: 1420498TR, N40.250 PRSTABZ100- (#4, 0.25″)
Farnell: 2770738TR, N4 0.250 PRST60 Z100 (#4, x 0.25″)
Mouser: ??
RS: 482-8054RS Pro, 482-8054 (#4 x 6mm)
RS: 483-1202RS Pro, 483-1202 (M3 x 5mm)

Homebrew 8-bit retro computing