Metallics JTSS1 6 x 1/2 in. Pan Head Square Drive Tapping Screws - Steel Zinc - Each

A #1 square (Robertson) bit. The JTSS1 uses a square recess with driver size 1R, and the recess measures 0.091 across flats with a gaging depth of 0.050 to 0.065 inch. Keep a fresh #1 square bit in the gun; the square recess holds the screw on the bit, which is why electricians favor it for overhead box and strap work.

It is a Type A tapping screw with a gimlet point, so it forms its own thread in sheet metal, and the sharp gimlet point starts in thin stock without a pilot in most sheet applications. Thread pitch is 18 threads per inch to ASME B18.6.4. Type A is a sheet-metal thread, not a machine thread, so it will not run into a tapped 6-32 hole in a device box.

No. The JTSS1 is neither Buy American compliant nor ARRA compliant, and country of origin is listed as multiple. On a federally funded job with domestic sourcing language, these will not qualify.

A #6 diameter screw, 1/2 inch long, with a pan head. The head runs 0.256 to 0.270 inch across and 0.087 to 0.097 inch high, so it sits low and wide enough to bear on a slotted strap or hanger without pulling through thin sheet.

They ship in a jar of 100, which is the order minimum. The jar weighs 0.26 lbs.

They are carbon steel with a zinc plating, which handles normal interior electrical, plumbing and HVAC environments. Zinc plating is a mild protective coating, not stainless, so for wet exterior or corrosive duty you want a stainless or hot-dip fastener instead.

They are case hardened to Rockwell C28-38 from AISI 1016-1024 steel, with a minimum torsional strength of 24 lb-in. That is enough to cut thread in light gauge steel, but at #6 diameter you should back off the clutch on an impact driver; overdriving is what shears a screw this size.

Head and recess dimensions follow ASME B18.6.3-2013, and the tapping thread follows ASME B18.6.4. Worth noting for anyone spec'ing across sizes: dimensions for the #9 diameter in this series fall outside ASME B18.6.4.

Electrical, plumbing, heating and air conditioning work. Typical use is fastening straps, clips, plates and light sheet metal parts where a short self-threading screw is quicker than drilling and bolting. At 1/2 inch long it is for thin stock, not for reaching through thick assemblies.