Metallics TP323SFC Screws 1/4-20 x 2 FH Span TR MS USA 1 (100 pcs)

It is a 1/4-20 x 2 inch screw, so 1/4 inch diameter with 20 threads per inch and a 2 inch length. Being a machine screw thread rather than a sheet metal or wood thread, it needs a tapped hole or a mating 1/4-20 nut to pull up tight.

A spanner (snake eye) bit, not a Phillips or hex key. The head has two round holes that a two-pin spanner bit engages, which is what makes it tamper resistant, and a 1/4 inch spanner bit is a separate purchase. If your crew does not already carry spanner bits, plan on adding them before the install, because no standard screwdriver will drive or back these out.

Yes. It is a flat head, which is a countersunk head designed to seat flush with the surface when the hole is countersunk or the plate is factory countersunk. That matters on cover plates, grilles, and panels where a protruding head would be grabbed or snag. If your part has a flat untapered hole, a flat head will stand proud, and you want a pan or truss head instead.

At 2 inches of overall length with a flat countersunk head, the usable grip is close to the full 2 inches because the head sinks into the material. Add up your panel thickness plus the thickness of what it threads into: if that total is under about 2 inches you are fine, and if the screw bottoms out in a blind tapped hole you will need a shorter length rather than this one.

Each pack is 100 pieces of the 1/4-20 x 2 inch flat head spanner screw, under part number TP323SFC. That quantity suits securing a run of panels or enclosure covers on one job rather than a single repair.

The TP323SFC is a machine screw (MS in the callout), made in the USA. For wet, coastal, or washdown locations, specify a stainless tamper-resistant screw instead of a plain steel one.