Metallics QK17W8M 8 x 1-1/2 in. 1/4 Hex Head Slotted Sharp Point Self-Piercing & Tapping Screws - Gray - Steel Zinc - Each

No. A sharp point self-piercing and tapping screw pierces and forms its own thread in thin sheet material as it drives, so no pre-drilling is required. The QK17W8M has twin lead threads to cut driving torque and 15 threads per inch, with an undercut under the head that gives you more thread engagement in the material.

The screw is case hardened to Rockwell C28-38 and made from AISI 1018 to 1022 steel, which is what lets the sharp point form threads in sheet material rather than deform against it. For thicker structural steel it is the wrong fastener; a self-drilling screw with a drill point is what you want there.

The QK17W8M ships as a box with an order minimum of 8,000 pieces. Metallics does make other sizes and quantities of this self-piercing screw available by request, so if 8,000 is more than the job needs, ask about an alternate pack.

The QK17W8M takes a 1/4 inch hex driver, and the hex head also carries a slot so you can back it out or set it with a flat blade when a nut driver won't fit the space. Measured head width runs 0.244 to 0.25 in. and head height 0.096 to 0.11 in., with a slot 0.045 to 0.054 in. wide and 0.052 to 0.074 in. deep.

It is zinc plated steel, which handles indoor and unconditioned interior work. Zinc plating is a sacrificial coating and is not a marine or constant-wet-exposure finish, so for exterior or washdown locations choose a stainless or coated exterior-rated fastener instead.

Yes, the head sits on a washer section measuring 0.322 to 0.348 in. outside diameter and 0.019 to 0.031 in. thick. That bearing surface spreads load on thin sheet so the head doesn't pull through, and it is why the head geometry differs from a standard tapping screw of the same nominal size.

Metallics lists the QK17W8M as both ARRA compliant and Buy American compliant, with country of origin recorded as multiple. If your specification demands a single documented origin for each lot, request origin documentation for the specific lot you are buying.

Treat them as a guide. Metallics states there is no single industry standard for self-piercing screw dimensions, and that head dimensions on these differ from standard tapping screws, so deviations from the listed head, slot and washer figures can occur. If the screw has to drop into an existing clip or bracket with a tight head clearance, verify against a sample.

The full box is listed at 56.8 lbs, with carton dimensions of 11.5 x 11.5 x 10.75 in. Worth knowing before you plan a single-person carry or a ladder haul to a roof deck.

Order it as Metallics QK17W8M, in the JQK series of self-piercing and tapping screws. It is a #8 diameter, 1-1/2 in. long screw with a 1/4 hex slotted head, sharp point, 15 threads per inch, in zinc plated steel.