Metallics JTSS9 8 x 1 in. Pan Head Square Drive Tapping Screws - Steel Zinc - Each

A #2 square (Robertson) bit. The JTSS9 specifies driver size 2R, and the recess measures 0.112 inch across flats with a gaging depth of 0.060 to 0.075 inch. Keep the bit seated fully; a worn #2 or a #1 bit will cam out before you reach the 39 lb-in torsional strength the screw is rated to carry.

The JTSS9 is a Type A tapping screw with a gimlet point, so it starts and forms its own thread in thin sheet metal, with 15 threads per inch on a 1 inch length. The gimlet point is the pointed, wood-screw-style tip, which is what lets it self-start in light-gauge stock. In thicker or harder steel you still want a pilot hole, because a Type A thread is designed for thin material, not structural plate.

No. The Metallics JTSS9 tapping screw is not Buy American compliant and is not ARRA compliant, and country of origin is listed as multiple. If your project carries a domestic sourcing clause, this is not the fastener to submit.

They are case hardened to Rockwell C28-38 from AISI 1016-1024 steel, with a minimum torsional strength of 39 lb-in. That is the normal range for a thread-forming tapper: hard enough to cut its own thread in sheet steel, and the 39 lb-in figure is the ceiling to respect if you are driving with an impact driver rather than a clutched screwgun.

Threads are to ASME B18.6.4 and head geometry to ASME B18.6.3-2013, with material per AISI 1016-1024. One caveat worth noting on a submittal: dimensions for the #9 diameter fall outside ASME B18.6.4.

The square recess on the JTSS9 has a square center opening with slightly tapered side walls and a conical bottom, so the bit holds the screw on the driver and resists cam-out. That matters when you are starting a screw one-handed overhead into a box or a duct hanger, where a Phillips tends to spin off the bit. The tradeoff is you need a #2 square bit (2R) on hand, not a standard #2 Phillips.

They ship in a jar of 100, which is the order minimum. The jar runs 0.59 lbs with stated carton figures of 3 in by 3 in by 2.15 in, so it drops into a van bin or gang box without repackaging.