Metallics TP221SFC Screws 1/4-20 x 2 FH Star Pin TR MS 18-8 (100 pcs)

It takes a pin-in-star (pin-in-Torx) bit, not a standard Torx. The TP221SFC has a post in the center of the six-lobe recess, so a solid Torx bit will not seat. You need the matching pin-in-star bit sized for a 1/4-20 flat head screw. Order the bits at the same time if your crew does not already carry a security bit set.

These are 18-8 stainless steel, the common 300-series austenitic grade used for general corrosion resistance. That makes them suitable for damp and outdoor-exposed locations such as exterior enclosures, fixtures, and public-access panels. For salt-spray or coastal marine exposure, 316 stainless is the step up.

The flat head on the TP221SFC sits flush in a countersunk hole, so there is no raised edge for a pry bar or pliers to grab and nothing protruding from the face of a cover plate or panel. That is the point on security applications. It does require the mating hole to be countersunk; if your part has a flat, un-countersunk hole, a pan or truss head is the better choice.

Being a machine screw, the TP221SFC threads into a 1/4-20 tapped hole or takes a 1/4-20 nut. It will not form its own thread the way a self-tapping or sheet metal screw does, so the mating part has to be tapped or you order 1/4-20 nuts separately. Nuts are not included with the 100-piece box.

Each box holds 100 pieces of the 1/4-20 x 2 inch pin-in-star flat head stainless screw, part number TP221SFC. That quantity suits standardizing a fleet of enclosures or public-facing covers across a facility rather than a single repair.