Metallics TP126SBC Screws 10-32 x 1 Btn Hx Pin TR MS 18- (100 pcs)

It takes a pin-in-hex (hex pin) driver bit, not a plain Allen key. The head is a button hex with a center pin, so a standard hex wrench will not seat. You need the matching pin-hex security bit in the size for a #10-32 button head.

Security. A pin-in-hex button head can only be removed with the matching security bit, so covers, junction boxes, panels and public-area fixtures stay closed to anyone carrying ordinary hand tools. For MRO and institutional work it is the same 10-32 thread as a standard machine screw, so it drops into existing tapped holes while locking out casual access. Specify the plain 10-32 machine screw instead where tooling for the pin-hex bit is not on hand.

The TP126SBC gives 1 inch of overall screw length under a button head, so it covers the thickness of what you are fastening plus enough thread engagement in the tapped hole. For thin cover plates on a shallow boss, 1 inch may bottom out or protrude past the back; measure the stack-up plus the depth of the tapped hole before committing to this length.

They are packed 100 pieces per box. That is a bulk pack sized for securing a run of enclosures, covers or fixtures rather than a single device, so one box covers a lot of openings before reordering.