Metallics TP819SOC Screws 10-24 x 1/2 OV Span TR MS 18-8 (100 pcs)

The TP819SOC is a 10-24 x 1/2 inch machine screw, sold 100 pieces to the box. 10-24 is the coarse machine screw thread, so it mates with a 10-24 tapped hole or nut, not a sheet metal or wood application. The 1/2 inch length is the shank under the head, which keeps it short enough for plate and cover work without bottoming out in a shallow tapped boss.

A spanner (snake eye) bit, not a Phillips or a flat blade. The TP819SOC head has two round drive holes set either side of center, so only a matching two-pin spanner bit or driver will turn it. Order the bit with the screws if you don't already carry one, because nothing in a standard bit set will drive or remove these.

18-8 stainless is the standard 300 series austenitic stainless used for general corrosion resistance, and it holds up in exterior and damp interior locations far better than plated carbon steel. It is not the choice for direct salt spray or coastal marine exposure, where a 316 stainless fastener is the right call.

Tamper resistance is about keeping the public out of the enclosure. On devices in corridors, schools, transit stops, restrooms, detention and other open-access areas, a standard Phillips cover screw can be backed out with a pocket tool. The TP819SOC's spanner head means removal needs a specific bit, so plates, device covers and junction box covers stay closed in a 10-24 tapped hole. For back-of-house or locked-room equipment, a standard 10-24 machine screw is the cheaper and easier call.

An oval head is a compromise head: the underside is tapered like a flat head, so it pulls down into a countersunk or chamfered hole, but the top is domed and stands slightly proud of the surface. The TP819SOC will not finish dead flush. If you need fully flush, you want a flat head in the same 10-24 x 1/2 size; if the hole in your plate is not countersunk, use a pan or truss head instead so the head bears on the face.

No. It's a machine screw, so it needs a pre-existing 10-24 tapped hole or a 10-24 nut. It has no self-drilling point and no sheet metal thread. For attaching to unthreaded sheet metal you want a self-tapping sheet metal screw, and for framing a wood or self-drilling screw. Use the TP819SOC where the threads already exist, which on electrical work is typically device mounting holes, plaster rings and box covers.

Order Metallics part number TP819SOC. That designation covers the 10-24 x 1/2 inch oval head spanner tamper-resistant machine screw in 18-8 stainless, 100 pieces.