Metallics QK16W-10M 8 x 1-1/4 in. 1/4 Hex Head Slotted Sharp Point Self-Piercing & Tapping Screws - Gray - Steel Zinc - Each

No pilot hole. The QK16W-10M is a sharp point self-piercing and tapping screw, so it pierces and forms its own thread in sheet metal as you drive it. Twin lead threads cut the driving torque, and the undercut under the head lets more of the thread engage the material.

They ship as a 10,000 piece box, which is also the order minimum. That is a jobber quantity rather than a contractor pack, so it suits an electrical shop or distributor stocking a single size rather than someone needing a handful.

Yes, the QK16W-10M is flagged both ARRA compliant and Buy American compliant, which matters on federal, municipal, and institutional work where the fastener spec gets audited with everything else.

Two options, same screw. The head is a 1/4 inch hex measuring 0.244 to 0.25 inch across, so a 1/4 inch magnetic hex driver bit is the normal choice for production work. It also has a slot, 0.045 to 0.054 inch wide and 0.052 to 0.074 inch deep, for a flat blade when a hex driver will not reach.

The integral washer head measures 0.322 to 0.348 inch outside diameter and 0.019 to 0.031 inch thick, giving a wider bearing surface than a plain hex head so it spreads load on thin sheet. It is an unsealed steel zinc washer, not a bonded or neoprene sealing washer.

The screws are case hardened to Rockwell C28-38 and made from AISI 1018 to 1022 steel, which is what lets the sharp point pierce and tap sheet steel without snapping the point. Zinc plated finish for indoor corrosion resistance.

Sharp point self-piercing screws like the QK16W are for thinner gauge sheet: the point punctures and the twin lead thread taps as it goes, with no pilot hole and no drill flute. Once you are into heavier gauge steel or bar stock the point will skate or stall, and a self-drilling point with a cutting tip is the right call instead. Note too that self-piercing head dimensions differ from standard tapping screws, so head clearance in a slotted hole should be checked against the 0.244 to 0.25 inch hex and the 0.322 to 0.348 inch washer OD.

15 threads per inch on a #8 diameter, 1-1/4 inch long screw. The 1-1/4 inch length gives plenty of reach for fastening through a box flange, clip, or strap into sheet metal, and the coarse twin lead pitch is what keeps driving torque down.

About 60.8 lbs for the full 10,000 piece box, in a carton roughly 11.5 x 11.5 x 10.75 inches. Worth knowing before it goes on a shelf or into a van.

No single industry standard governs self-piercing screw head dimensions, so Metallics publishes the QK16W figures as a guide and small deviations can occur. If the head has to clear a tight recess, work off the ranges given: 0.244 to 0.25 inch head width and 0.096 to 0.11 inch head height.