Metallics QK17GR8M 8 x 1-1/2 in. 1/4 Hex Head Slotted Sharp Point Self-Piercing & Tapping Screws - Gray - Steel Zinc - Each

Two options on the QK17GR8M. The hex head measures 0.244 to 0.25 inches across, so a 1/4 inch hex driver or socket seats it. The head is also slotted (slot width 0.045 to 0.054 inch, depth 0.052 to 0.074 inch), so a flat blade driver works where a nut driver will not fit, like tight panel work.

No. The QK17GR8M has a sharp point that pierces and taps its own hole in sheet metal, so there is no pre-drilling and no separate tap. Twin lead threads cut the driving torque, and the undercut under the head gives you more thread engagement once it is seated.

Yes, that is what it is built for. The screw body is AISI 1018 to 1022 steel case hardened to Rockwell C28-38, which is hard enough to form threads in light gauge sheet and stud material while the shank stays tough. At 15 threads per inch with twin leads it pulls in fast. In structural or heavy plate it is the wrong fastener, use a drill point screw or a drilled and tapped machine screw.

The QK17GR8M ships as a box with an order minimum of 8,000 pieces, at roughly 56.8 lbs for the carton. That is a stocking quantity for a shop or a repeat panel job, not a one-off repair. Metallics does make other sizes and quantities in this line available by request.

It has an integral washer face with an outside diameter of 0.322 to 0.348 inch and a thickness of 0.019 to 0.031 inch. That spreads the clamp load over a wider footprint than the 1/4 inch hex alone, which matters when you are fastening thin sheet or a soft panel and do not want the head pulling through. Head height runs 0.096 to 0.11 inch, so it sits low.

The QK17GR8M is flagged both ARRA compliant and Buy American compliant in Metallics' data. Country of origin is listed as multiple, so if your specification requires a single named origin on the submittal, that is the detail to pin down with the mill certification rather than the catalog flag.

The QK17GR8M is zinc plated carbon steel with a gray head. Zinc plating is an indoor and sheltered-use finish, fine for panel interiors, enclosures, and dry electrical work. For sustained exterior exposure, washdown, or coastal air, move to a stainless or coated exterior-rated fastener instead, plated steel will rust at the cut threads where the point breaks through.

Because there is no single industry standard for self-piercing screw head dimensions. Metallics publishes the values on the QK17GR8M, a 0.244 to 0.25 inch hex and 0.096 to 0.11 inch head height, as a guide, and notes deviations can occur. If you are matching an existing head for appearance or for a fixed-depth counterbore, verify against a sample before you commit to a full box.