Metallics QK155M 8 x 1 in. 1/4 Hex Head Slotted Sharp Point Self-Piercing & Tapping Screws - Steel Zinc - Each

No. The QK155M is a sharp point self-piercing and tapping screw, so it pierces thin sheet and forms its own thread as it drives. Twin lead threads cut the driving torque, which matters when you are running hundreds of them into studs, strut, or enclosure sheet by hand drill. For thicker material where the point will not penetrate, you want a drill point (self-drilling) screw instead.

Both the ARRA and Buy American compliance flags on the QK155M are marked compliant. Country of origin is listed as multiple, so if your specification requires documented origin for a specific shipment, request the certification with the order.

Not necessarily. Metallics states that head dimensions of self-piercing screws differ from those of standard tapping screws, and that there is no single industry standard for self-piercing screw dimensions, so the published figures are a guide and deviations can occur. If the head has to seat in an existing counterbore or under a fixed clip, measure against the 0.244 to 0.250 inch head width and 0.096 to 0.110 inch head height before committing to a full 5,000 piece box.

Either works. The QK155M has a hex head measuring 0.244 to 0.250 inch across, so a 1/4 inch hex driver or nut setter seats on it, and the head is also slotted (slot width 0.045 to 0.054 inch, depth 0.052 to 0.074 inch) if you need to run it with a flat blade in tight quarters. Most crews use the hex drive for speed and keep the slot for hand adjustment.

It is a #8 diameter by 1 inch long screw with 15 threads per inch. The 1 inch length plus the undercut below the head gives you more thread engagement than a standard tapping screw of the same nominal length, which is what you want when fastening through a strap or clip into light gauge metal.

They ship in a box of 5,000 pieces, which is the order minimum. Shipping weight on the box is 24.48 lbs and the carton measures 9 x 9 x 6.13 inches. Metallics notes other sizes and quantities are available on request, so if you need a shorter length or a different pack for a smaller job, ask.

The QK155M is AISI 1018 to 1022 steel with a zinc finish, case hardened to Rockwell C28-38. Zinc plating is a mild corrosion barrier intended for dry interior and protected locations, electrical enclosures, interior duct and strut work. For direct exterior exposure, washdown areas, or coastal humidity, specify a stainless or coated exterior fastener instead.

Yes, the head carries a built-in washer face with an outside diameter of 0.322 to 0.348 inch and a thickness of 0.019 to 0.031 inch. Head height is 0.096 to 0.110 inch. That washer OD is what spreads the bearing load on sheet metal, so no separate washer is required for typical sheet fastening.