Metallics QK30M 10 x 1 in. 1/4 Hex Head Slotted Sharp Point Self-Piercing & Tapping Screws - Steel Zinc - Each

Either works. The QK30M has a 1/4 inch hex head with a slotted drive, so you can run it with a 1/4 inch hex socket or magnetic nut driver, or back it out with a #8 slotted screwdriver bit. The slot measures 0.045 to 0.054 inch wide and 0.052 to 0.074 inch deep, so a standard #8 blade seats properly without camming out.

That is the point of it. The QK30M is a sharp point self-piercing and tapping screw, so it pierces and forms its own thread in sheet metal with no pilot hole. Twin lead threads cut the driving torque, and the hardened body (Rockwell C28-38 on AISI 1018-1022 steel) is what lets the point bite instead of deform. For thicker structural steel you want a drill point screw instead.

No, and that matters if you are matching existing fasteners. Metallics states outright that head dimensions on self-piercing screws differ from standard tapping screws, and there is no single industry standard for self-piercing screw dimensions. On the QK30M the hex head measures 0.244 to 0.250 inch across with a head height of 0.096 to 0.110 inch, and the integral washer runs 0.384 to 0.414 inch OD at 0.019 to 0.031 inch thick. Treat those as a guide, since deviations can occur.

No. The QK30M is not Buy American compliant and is not ARRA compliant, with country of origin listed as multiple. If your project carries a domestic sourcing clause, this screw will not satisfy it.

They ship in a jar of 1,000, which is also the order minimum. The filled jar weighs 7.1 lbs. Metallics does list other sizes and quantities as available by request, so a different count is a special order rather than something you pick off the shelf.

They are made for electrical, plumbing, heating and air conditioning work, which is duct seams, strut, conduit straps, and panel work. The material is zinc plated steel, a dry interior finish. For exposed exterior or damp locations, specify a stainless or coated exterior fastener instead.

12 threads per inch on a #10 diameter, 1 inch long shank. The undercut area beneath the head gives you more usable thread length for the same overall screw, so you get deeper engagement into thin material instead of running the thread straight up under the washer.