Metallics TP611SFC Screws 10 x 1-1/4 FH Star Pin TR SMS 18-8 (100 pcs)

It is a #10 x 1-1/4 inch flat head sheet metal screw in 18-8 stainless steel, with a star (Torx style) drive that has a pin in the center of the recess, making it tamper resistant. Metallics sells it under part number TP611SFC in boxes of 100 pieces.

Yes. The center pin in the star recess blocks a standard Torx bit, so you need a pin-in-star (Torx-with-hole) security bit in the matching size. A plain Torx or Phillips driver will not seat. Order the bits with the screws if your crew does not already carry security bits, or the fasteners sit unused on the truck.

Tamper resistance is the whole point of the pin in the star recess: once installed, the screw cannot be backed out with common bits found in a pocket screwdriver set. That matters on covers, enclosures, panels, guards and public-area fixtures where you do not want the general public opening things up. For normal fastening where access is not a concern, a standard Phillips or Torx sheet metal screw is cheaper and faster to drive.

The screw is 18-8 stainless, the common austenitic grade (roughly equivalent to 304), which handles outdoor and wet interior exposure far better than plated carbon steel. For direct coastal salt spray or pool chemical exposure, 316 stainless is the better call.

Flat head means a tapered, countersunk head, so it finishes flush with the surface only if the hole is countersunk or the material is thin enough to dimple. In sheet metal, use a countersunk punched hole; in flat plate or solid stock, countersink first. If you need the head to sit on top of the surface instead, a pan or truss head sheet metal screw is the one to order.

Sheet metal screw threads are fully threaded with a sharp, coarse pitch cut for thin metal, plastic and composite. A #10 x 1-1/4 inch SMS holds well in sheet steel, aluminum and enclosure housings with a properly sized pilot hole. It is not a wood screw or a drywall screw, and it is not a self-drilling screw either, so drill or punch your hole first.

Each box holds 100 pieces, which is the standard take-along quantity for a security-fastener retrofit across a run of covers or enclosures. For larger standardization work, order in multiples of the 100-count box.