Metallics JTSS27 10 x 3/4 in. Pan Head Square Drive Tapping Screws - Steel Zinc - Each

A #2 square bit. The JTSS27 uses a square recess with a 2R driver size, and the recess measures 0.112 across flats with a gaging depth of 0.060 to 0.075 inch. A standard #2 Robertson/square bit seats fully; a #1 will cam out and a #3 will not enter.

The JTSS27 is a Type A tapping screw with a gimlet point, which is the sharp pointed style made to start in thin sheet metal and pull itself in. In light-gauge sheet it will start on its own; in heavier stock you still want a pilot. Thread pitch is 12 threads per inch to the ASME B18.6.4 thread standard, so it is a coarse-thread sheet metal screw rather than a machine screw.

No. The JTSS27 is not Buy American compliant and is not ARRA compliant, and country of origin is listed as multiple. On a federally funded job with domestic sourcing requirements you will need a domestically produced fastener instead.

No. It is a Type A sheet metal tapping screw with a gimlet point and 12 threads per inch to ASME B18.6.4, so the thread form will not mate with a tapped #10-24 or #10-32 hole. It cuts its own thread in sheet metal. For a threaded hole or a nut you need a machine screw.

They come packed in a jar, 100 screws per jar, and the jar is the order minimum. Jar weight is 0.62 lbs. If you need a different size or a different count, Metallics offers other sizes and quantities by request.

These are carbon steel with a zinc plating, made from AISI 1016 to 1024 steel. Zinc plate is a dry-location and indoor-grade finish, fine for panel work, strut, enclosures, and duct inside a building. For exterior, wet, or corrosive locations, go to a stainless steel or hot-dip galvanized sheet metal screw instead.

Torsional strength on the JTSS27 is 48 lb-in minimum, with case hardness at Rockwell C28-38. That is enough for hand driving or a clutched screwgun; a high-torque impact driver can exceed 48 lb-in and twist the shank once the screw bottoms out, so back the torque off or set the clutch.

Metallics lists the JTSS27 for the electrical, plumbing, heating and air conditioning industries. In practice that is panel and enclosure work, mounting devices and brackets to sheet metal, and fastening duct and hanger hardware. The square recess is the reason the trades like it: a #2 square bit holds the screw on the bit one-handed overhead, which a Phillips will not do.