Metallics JTEKD90 14 x 2-1/2 in. 3/8 Indented Hex Head Self-Drilling & Tapping Screws with Washer - #3 Drill Point - Steel Zinc - Each

A 3/8 inch hex socket or nutdriver bit. The JTEKD90 has an indented hex washer head with a hex drive, head width running 0.367 to 0.375 in. and 0.409 in. across the corners, so a standard 3/8 magnetic nutsetter in a drill or impact driver seats on it cleanly. No bit tip is needed.

No pilot hole. The #3 drill point on the JTEKD90 drills and taps its own hole in one pass, which is the whole point of a Type BSD self-drilling and tapping screw. A #3 point is the mid-range point sized for heavier gauge steel than the #2 you would use on light stud track. Reference drill time is about 2.5 seconds through a 1 mm plate.

Overall screw length is 2-1/2 in. at a #14 diameter with 14 threads per inch, so your combined grip, the strap or bracket plus the steel you are drilling into, has to leave enough thread engagement past the drill point. That length is sized for stacked assemblies: through wood blocking, insulation, or a thick spacer into steel, rather than sheet-to-sheet work where a 3/4 or 1 in. screw is the right call.

It is an integral washer formed as part of the indented hex washer head, so there is nothing loose to handle on the ladder. Washer outside diameter runs 0.480 to 0.520 in. with a washer thickness of 0.030 to 0.050 in., giving a wider bearing face than a plain hex head for clamping strap, clip, or sheet metal without pulling through.

The JTEKD90 is zinc plated carbon steel, which suits dry interior and protected service: electrical rough-in, strut and strap anchoring, ductwork, interior framing. Zinc plating is a sacrificial coating, not a stainless substitute, so for sustained exterior exposure, roofing, coastal air, or wet process areas choose a stainless or coated-for-exterior self-drill screw instead.

Three specs cover the JTEKD90: ASME B18.6.3-2010 for head dimensions, SAE J78-2013 for the thread and drill screw requirements, and AISI 1016-1024 for the steel. Case hardness is Rockwell C32-40. Note that SAE J78 does not cover #7 diameter drill screws, so if a drawing calls out a #7 you are outside that standard.

The JTEKD90 is flagged compliant for both Buy American and ARRA, which is what a government, school district, or federally funded institutional buyer needs on the submittal. Country of origin is listed as multiple, so confirm the origin marking on the jar you receive if your contract requires a single named country.

They ship in a jar with a 100 count order minimum, so one jar of 100 is the smallest buy. Shipping weight of the jar is listed at 2.84 lbs. For an MRO crib or a repeat electrical rough-in, that count is the standard stocking unit.

Head height on the JTEKD90 runs 0.172 to 0.19 in., plus the integral washer at 0.030 to 0.050 in. thick. That matters where a panel, cover, or enclosure has to sit flat over the fastener, since an indented hex washer head does not countersink; it bears on the surface. For flush work you need a flat or pan head screw instead.