Metallics TP520SBC Screws 6 x 3/8 Btn Hx Pin TR SMS 18-8 (100 pcs)

The TP520SBC is a #6 x 3/8 inch sheet metal screw (SMS), so it takes a self-tapping sheet metal thread rather than a machine thread. Head style is button head with a hex socket and a center pin, which is what makes it tamper resistant. Sold 100 pieces to the box.

It needs a pin-in-hex (hex pin) security bit, not a standard hex key. A plain hex driver bottoms out on the center pin in the recess, which is the whole point of the design: it keeps the fastener off limits to anyone carrying only a normal bit set. Size the bit to a #6 button head hex pin screw.

18-8 is the common austenitic stainless grade (roughly 18 percent chromium, 8 percent nickel) and resists general atmospheric and humid-environment corrosion, so it is the usual choice for exterior enclosures, damp plant rooms, and washdown areas where a plated carbon steel screw would rust. It is not the grade to choose for direct, continuous salt-spray or coastal immersion exposure, where 316 stainless is specified instead.

At 3/8 inch of total length, the TP520SBC is meant for thin material: sheet metal covers, device plates, enclosure doors, and lids where only a few threads of engagement into gauge steel are needed. If you are fastening through a thicker stack or into a boss, step up to a longer screw, because 3/8 inch will not reach.

Security. In public corridors, transit areas, schools, restrooms, and anywhere a cover or enclosure is reachable, a pin-in-hex button head stops casual removal with the bits people carry. Function is otherwise the same as a standard #6 x 3/8 SMS, and the low button profile keeps the head from snagging. The tradeoff is that your own crew has to carry the matching security bit for service calls.

100 pieces per box of the #6 x 3/8 inch button head hex pin stainless sheet metal screws. For standardizing a facility on one security fastener, order by the box and keep one matched pin-in-hex bit per tech.