Metallics JTSS30 10 x 1-1/2 in. Pan Head Square Drive Tapping Screws - Steel Zinc - Each

A #2 square (Robertson) bit. The recess is specified as driver size 2R, with a recess width across flats of 0.112 inch and a gaging depth of 0.060 to 0.075 inch, so a standard #2 square driver seats fully. A #1 will cam out and a #3 won't enter.

The JTSS30 is a Type A tapping screw with a gimlet point, which is the sharp, spaced-thread point made for thin sheet metal and soft materials. In light gauge sheet it will start and form its own thread; in heavier gauge steel you still want a pilot hole, because Type A threads are coarse (12 threads per inch here) and are not designed to cut through thick stock the way a self-drilling screw does.

Yes. Head and recess dimensions on the JTSS30 are built to ASME B18.6.3-2013, the thread form to ASME B18.6.4, and the steel to AISI 1016-1024. Note that the product is listed as neither ARRA compliant nor Buy American compliant, with country of origin shown as multiple, so it will not satisfy a domestic-content requirement on a federal job.

Yes. Metallics lists the JTSS30 for the electrical, plumbing, and heating and air conditioning trades, which is the usual home for a #10 pan head Type A tapping screw: box and enclosure mounting, duct and sheet metal joints, and strap or clip fastening into wood or light metal. The pan head gives a broad bearing surface that won't pull through a punched mounting hole.

The JTSS30 is case hardened to Rockwell C28-38 from AISI 1016-1024 steel, with a minimum torsional strength of 48 lb-in. That is the twist-off threshold, so on an impact driver set to high you can snap one before the thread seizes. Drop the clutch setting and keep the #2 square bit fully seated.

These are steel with a zinc finish, which is a plated coating for indoor and protected use. It handles ordinary jobsite humidity, but zinc plating is not a marine or sustained-wet coating; for exterior exposure, wet locations, or treated lumber contact, specify a stainless or hot dip galvanized fastener instead.

They ship in a jar of 100, and 100 is the order minimum. The packed jar weighs 1.02 lbs. Metallics does make other sizes and quantities available by request if 100 of the #10 x 1-1/2 in. is not the count you need.

Square drive is the better pick overhead. The square recess on the JTSS30 has a tapered-wall, conical-bottom socket that grips a #2 square bit well enough to hold the screw on the bit one-handed, where a Phillips recess cams out under the same load. If your crew is already standardized on Phillips bits, that is the only real argument the other way.