Metallics QK1M 7 x 1/2 in. 1/4 Hex Head Slotted Sharp Point Self-Piercing & Tapping Screws - Steel Zinc - Each

Two ways to drive it. The head is a 1/4 inch hex measuring 0.244 to 0.25 inch across, so a 1/4 inch hex driver or socket seats on it directly. It also has a slotted drive, slot width 0.039 to 0.048 inch and depth 0.04 to 0.062 inch, taking a #8 slotted driver bit. Useful when you are working in a tight spot where a socket will not fit over the head.

No pilot hole needed in sheet metal. These are sharp point self-piercing and tapping screws, so the point pierces the material and the thread forms its own mating thread as it drives. Twin lead threads cut the driving torque, and the undercut under the head gives you more thread engagement. 16 threads per inch on a #7 diameter, 1/2 inch long shank.

No. The QK1M is not Buy American compliant and is not ARRA compliant, and country of origin is listed as multiple. For a federally funded job with domestic sourcing requirements you need a fastener carrying a Buy American compliant designation instead.

They are a trade fastener for electrical, plumbing, heating and air conditioning work. Typical use is fastening into sheet metal and light gauge material where you cannot get behind the work to pre-drill: duct, panels, boxes, strap and hanger attachment. The integral washer face (0.322 to 0.348 inch outside diameter, 0.017 to 0.029 inch thick) spreads the load against thin sheet.

Steel with a zinc finish, so it is suited to dry interior and incidental-damp work rather than sustained wet or corrosive exposure. The steel is AISI 1018 to 1022 case hardened to Rockwell C28-38, which is what lets the sharp point pierce sheet metal without rolling over.

Sold in a jar of 1,000 pieces, which is also the order minimum. The packed jar weighs 2.76 lbs and measures 3 in by 3 in by 4.57 in, so it drops into a van bin or gang box without repacking.

Head height runs 0.08 to 0.093 inch, so it sits close to flush against the sheet, with the washer face beneath it bearing on the surface. Worth noting 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 treat these figures as a guide where a tight clearance matters.

The QK1M itself is the #7 diameter, 1/2 inch long version in the Metallics JQK hex head slotted sharp point self-piercing series. Metallics builds the same screw in other sizes and pack quantities, and those are available by request.