Metallics QK1510M 8 x 1 in. 1/4 Hex Head Slotted Sharp Point Self-Piercing & Tapping Screws - Steel Zinc - Each

No pilot hole. The QK1510M is a sharp point self-piercing and tapping screw, so it pierces and forms its own thread in sheet metal as it drives. Twin lead threads cut the driving torque, and the undercut under the head gives you more thread engagement once it seats.

Either a 1/4 inch hex driver or a flat blade. The head is hex with a 0.244 to 0.25 inch width across flats, so a 1/4 inch magnetic hex bit or nut driver seats it, and the slotted drive gives you a flat-screwdriver fallback in tight spots. Slot width runs 0.045 to 0.054 inch and slot depth 0.052 to 0.074 inch, so use a thin cabinet-tip blade, not a wide general-purpose one.

Metallics lists the QK1510M as both Buy American compliant and ARRA compliant. Country of origin is listed as multiple, so if your contract requires a single named country of manufacture on the submittal, that is the detail to confirm on the lot you receive.

They ship as a box of 10,000 pieces, with 10,000 as the order minimum. Carton weight is 54 lbs and the box measures 7.25 x 6.25 x 6 inches. That is a bulk production quantity rather than a job-box count, so it suits an electrical contractor or MRO stockroom standardizing on one sheet metal screw rather than someone needing a handful.

A #8 diameter by 1 inch long screw at 15 threads per inch. The 1 inch length is the usable grip depth into metal studs, hangers, or sheet metal duct, so account for material thickness plus whatever you are fastening through when you pick the length.

The head carries an integral washer section with an outside diameter of 0.322 to 0.348 inch and a washer thickness of 0.019 to 0.031 inch. Head height is 0.096 to 0.11 inch. That washer face spreads load on thin sheet so the head does not pull through, which is why it works for hanging strap, clips, and light sheet metal without adding a separate washer.

Hardness is Rockwell C28-38 on AISI 1018-1022 steel, which is what lets the point pierce and thread sheet steel instead of deforming. Finish is zinc plated steel. Zinc plating is an indoor and dry-location coating, so for exterior or damp runs choose a fastener with a coating rated for that exposure.

Not exactly. Metallics notes that head dimensions on self-piercing screws differ from standard tapping screws, and there is no single industry standard for self-piercing screw dimensions, so the published values are a guide and some deviation can occur. If you need the head to look and seat identically to existing fasteners on finished work, pin it down against a sample rather than assuming the two interchange visually.

Order it as Metallics QK1510M, part of the JQK series of self-piercing and tapping screws. Metallics notes other diameters, lengths, and quantities in the same family are available by request.