Metallics JSTSP21316 Screw 10 x 3/4 PN PH TS 316 SS (Jar 100)

It's a #10 x 3/4 inch pan head Phillips tapping screw in 316 stainless steel. The pan head sits low and flat-bottomed, so it bears on sheet metal or a strap without needing a countersunk hole, and the Phillips recess drives with a standard #2 bit.

For salt air, pool rooms, wastewater, or roof-mounted equipment, yes. The JSTSP21316 is 316 stainless, the molybdenum-bearing grade that resists chloride pitting far better than 18-8 (304). On dry interior work 18-8 is normally sufficient; the 316 is what you reach for when the fastener will see salt spray or washdown chemicals.

Tapping screws like this one cut their own thread in the material, but they are not self-drilling, there is no drill point on the end. You need a pilot hole in sheet metal, strut, or enclosure wall before driving. In softwood or plastic a pilot is optional but keeps the 3/4 inch length from splitting the material.

For sheet metal, strut, or an enclosure wall, 3/4 inch of #10 gives plenty of thread engagement, that application typically needs only a few threads past the material. Where it falls short is anchoring through drywall into a stud or through thick backing, which needs a longer fastener. Measure your stack-up: material thickness plus at least three engaged threads has to come in under 3/4 inch.

They ship in a jar of 100. The jar keeps the loose screws contained on a service truck or in a parts bin, which is the usual way MRO and electrical crews stock a common size like #10 x 3/4.

Metallics part number JSTSP21316, a #10 x 3/4 pan head Phillips tapping screw in 316 stainless, jar of 100. That MPN is the one to quote when ordering or matching a prior purchase.