Metallics JTEKD20 12 x 3/4 in. 5/16 Indented Hex Head Self-Drilling & Tapping Screws with Washer - #3 Drill Point - Steel Zinc - Each

The #3 drill point on the JTEKD20 is rated for panel thickness of 0.110 to 0.210 inches, so roughly 12 gauge down through 7 gauge steel. Thinner sheet than 0.110 can be done but the point is sized for that range, and anything over 0.210 needs a longer drill point. Metallics cites a drill time of about 2.5 seconds in a 1 mm thick plate.

No. The JTEKD20 is not Buy American compliant and is not ARRA compliant, with multiple countries of origin. If your spec carries a domestic sourcing clause, you need a documented domestic fastener instead.

The washer is part of the screw head, not a loose piece. It measures 0.398 to 0.432 inches outside diameter and 0.022 to 0.039 inches thick, which spreads the bearing load on sheet metal and on strap or clamp flanges without a separate washer to handle on a ladder.

These ship in a jar of 100 with a 100 piece minimum, so one jar is the smallest buy. Jar weight is listed at 0.81 lbs. Metallics also offers other diameters, lengths and pack quantities in the same JTEKD series by request.

The JTEKD20 is carbon steel with a zinc plating, which is a dry indoor and protected finish. On exposed rooftop curbs, condensing units or anywhere washed by rain or coastal air, zinc plate will rust at the drill chips and the cut threads. Use a stainless or coated self-drilling screw for those locations and keep the zinc version for indoor panel, conduit strap, duct and interior equipment mounting.

Head dimensions are to ASME B18.6.3-2010 and the thread is to SAE J78-2013. The steel is AISI 1016 to 1024 case hardened to Rockwell C32-40 with a minimum torsional strength of 92 lb-in, which is the number that matters if you are driving with an impact and snapping heads.

Metallics lists these for the electrical, plumbing, heating and air conditioning trades. In practice that means mounting straps, clamps, boxes, duct, hangers and equipment panels to steel without pre-drilling, since the type BSD point drills and taps in one pass.

No pilot hole. The #3 drill point cuts its own hole and the 14 TPI thread taps it in the same pass, which is the point of a type BSD screw. Drive it square and let the point do the work before putting weight into it, otherwise the tip walks and work-hardens the steel.