Metallics TP531SBC Screws 14 x 5/8 Btn Hx Pin TR SMS 18- (100 pcs)

It's a #14 diameter screw with a 5/8 inch length, button head, in a sheet metal screw thread. Sold 100 pieces to the pack under part number TP531SBC. The 5/8 inch length is a short screw, so it suits thin sheet metal, enclosure covers, strut accessories and similar attachments rather than anything needing deep penetration.

A pin-in-hex (hex pin) tamper resistant bit, not a plain hex key. The recess has a post in the center, so a standard Allen wrench or hex bit will not seat. You need a pin hex bit sized to the screw, and standard security bit sets carry them. Plan on having the right bit on the truck before install, because nothing else will drive or remove it.

The hex pin drive is a genuine tamper resistant recess, which is why Metallics designates it TR. The center pin blocks a common hex key, so a passer-by with a standard tool set can't back it out. It's the usual choice for public-facing covers, panels, signage and fixture guards where you want to keep casual hands off. It is not a one-way screw, though: anyone with a pin hex bit can remove it, which is what you want for service access.

Sheet metal screw threads are designed to cut their own thread in sheet steel, aluminum and thin plate; they are not machine screw threads, so they will not take into a tapped hole or a nut. For an electrical enclosure, strut accessory or cover plate you drill a pilot and let the screw form its own thread. If your hole is already tapped to a machine thread, this is the wrong screw and you want a machine screw instead.

100 pieces per pack. For a maintenance shop or an MRO crib that standardizes security fasteners across a building, that is enough to stock a van and still leave spares, and it keeps one part number on the shelf instead of mixing head styles across openings and enclosures.

A button head sits in a low, rounded dome above the surface, so it needs no countersink and gives very little purchase for pliers or vise grips, which matters on a tamper resistant fastener. A flat head would require a countersunk hole in the sheet; a pan head stands taller with a sharper shoulder edge. If the finished surface has to be flush, this button head version is not the one.