Metallics TP522SBC Screws 8 x 3/8 Btn Hx Pin TR SMS 18-8 (100 pcs)

The TP522SBC is a pin-in-hex (hex pin) tamper resistant sheet metal screw, so a standard hex key will not seat. You need a pin-in-hex security bit sized to the screw's socket, with the center hole that clears the pin. A plain Allen wrench or Torx bit will not drive it.

Sheet metal screw threads cut their own path in thin metal and plastic, so a #8 self-threads into an unthreaded sheet metal hole sized for it. Device plate screws on standard wiring devices are machine screws (6-32), and the TP522SBC will not thread into a 6-32 tapped hole. Use it for sheet metal panels, covers, and guards with drilled or punched clearance holes, not for 6-32 device prep.

They're 18-8 stainless, which is the common 300 series austenitic grade used for general corrosion resistance. That makes the TP522SBC suitable for damp and outdoor enclosure work where a plated carbon steel screw would rust. For salt spray or coastal exposure, 316 is the step up.

A button head sits on top of the surface and needs no countersink, so it works on sheet metal and panels with plain round holes, which is most electrical covers and guards. A flat head tamper screw needs a countersunk or dimpled hole to sit flush. If your cover isn't countersunk, the button head TP522SBC is the one that seats correctly.

Sold 100 pieces to the box under part number TP522SBC. That's a practical count for a maintenance crew securing cover plates, guards, or vandal-prone device plates across a building, since tamper screws are usually consumed a handful at a time per opening.