Metallics JTEKD12V 10 x 3/4 in. 5/16 Indented Hex Head Self-Drilling & Tapping Screws with Washer - #3 Drill Point - Steel Zinc - Each

Minimum torsional strength on the JTEKD12V is 61 lb-in, which is well under what a full-power impact will deliver. Use a screw gun with a clutch or depth-sensing nose piece, or dial your impact down. Drill time through a 1 mm plate is about 2.5 seconds; if it is taking much longer, the point is dull and continued pressure is what breaks heads off.

Yes, within the thickness range. A Type BSD self-drilling and tapping screw with a washer head is the standard way to fasten strut, boxes, and brackets to metal framing or sheet steel from 0.110 to 0.175 inch thick. At 3/4 inch long the screw gives you useful grip after the panel, so stack thickness of the item you are mounting plus the panel has to stay under that. Typical 25 gauge interior metal stud is far thinner than 0.110 inch, so for light stud work a smaller point size is the better match.

A 5/16 inch hex driver or nut setter. The head is an indented hex measuring 0.305 to 0.312 inch across the flats and 0.34 inch across the corners, with hex drive only, no slot or Phillips option. A magnetic nut setter is the usual choice because the indented top helps the bit stay seated while the point drills.

It is a steel bonded washer head, not a sealing washer. Outside diameter runs 0.384 to 0.414 inch with a washer thickness of 0.019 to 0.031 inch, which spreads the clamp load over sheet metal and keeps the head from pulling through thin panel. If you need a weather seal on a roof or exterior panel, you want a screw with an EPDM bonded washer instead.

The JTEKD12V is carbon steel with a zinc finish, which is fine for interior and dry or occasionally damp conditions. Zinc plating is not a marine or sustained-wet coating, so for exterior corrosive exposure specify a stainless self-drilling screw. The base steel is AISI 1016 to 1024 case hardened to Rockwell C32-40.

Dimensions are to ASME B18.6.3-2010 and threads to SAE J78-2013, UNC form at 16 threads per inch on a #10 diameter. Note that SAE J78 does not cover #7 diameter drill screws, so a #7 submittal will not reference it. The item is flagged both ARRA compliant and Buy American compliant, with multiple countries of origin.

They ship in a jar of 500 count, which is the order minimum, and the jar weighs 3.1 lbs. Other sizes and quantities are available by request.

Head height is 0.105 to 0.12 inch plus a washer 0.019 to 0.031 inch thick, so you are looking at roughly a tenth to a seventh of an inch of profile above the panel, in a silver zinc finish. That matters if something has to sit flat over the fastener; for a flush surface you need a flat head or pancake head screw instead.