Metallics JTEKD88 8 x 2-1/2 in. 1/4 Indented Hex Head Self-Drilling & Tapping Screws with Washer - #2 Drill Point - Steel Zinc - Each

The #2 drill point on the JTEKD88 is rated for panel thickness of 0.035 to 0.100 inch, so it drills and taps its own hole in light to medium gauge steel such as studs, strut, hat channel and sheet metal in that range. Thicker material than 0.100 inch is outside what this point is rated to drill, and you would need a heavier drill point or a pre-drilled hole.

Metallics lists the JTEKD88 as both Buy American compliant and ARRA compliant. Country of origin is China. If your contract documents require domestic melt and manufacture rather than the compliance designation on the catalog record, verify that against the spec section governing your job.

Minimum torsional strength on the JTEKD88 is 42 lb-in, with case hardness of Rockwell C32-40. That is enough for normal driving in 0.035 to 0.100 inch steel, but a high-torque impact driver will exceed 42 lb-in easily once the head seats. Drive to seat and stop, or dial the clutch back on a screw gun. Typical drill time is about 2.5 seconds through a 1 mm plate.

It takes a 1/4 inch hex driver. The head is an indented hex with hex drive, measuring 0.244 to 0.25 inch across the flats and 0.272 across the corners, with a head height of 0.096 to 0.11 inch. A standard 1/4 inch magnetic nut setter in a drill or impact driver is the right tool.

They ship in a jar, with a minimum order of 100 count. That is the sell quantity, so ordering one unit gets you the 100-piece jar rather than a single screw.

The JTEKD88 carries an integral steel washer, 0.322 to 0.348 inch outside diameter and 0.019 to 0.031 inch thick. It spreads clamp load and keeps the head from pulling through thin sheet, but it is bare steel with no bonded gasket, so it is not a weather seal. For exterior roof or siding penetrations you want a bonded EPDM-washer screw instead.

The JTEKD88 is zinc plated carbon steel to AISI 1016-1024. Zinc plating suits dry interior work, concealed ceiling space and electrical rooms. Sustained exposure to weather, chlorides or wash-down will corrode it, and in those locations a stainless self-drilling screw is the correct call. Minimum driving torque is the same for stainless and steel self-drillers, so switching material does not change how you install it.

18 threads per inch on a #8 diameter, 2-1/2 inch long shank, built to SAE J78-2013 for the thread form and ASME B18.6.3-2010 for head dimensions. That is the standard Type BSD self-drilling and tapping thread, so it taps its own mating thread in sheet steel as it drives, no nut or anchor needed.

That is what the length is for. At 2-1/2 inches the JTEKD88 has enough reach to pass through finish material or a standoff and still drill and tap into the stud or channel behind, provided the steel it lands in is 0.035 to 0.100 inch thick. Shorter self-drillers in the same series handle direct metal-to-metal attachment where no standoff is involved.