Metallics QDS171 12 x 1 in. 5/16 Hex Head Quadrive Sharp Point Tapping Screws - Steel Zinc - Each

The QDS171 is a #12 diameter by 1 inch long tapping screw with a 5/16 hex head. The Quadrive head accepts more than just a hex driver: it takes hex, slotted, Phillips, and square drive, so you can run it with a 5/16 nutsetter in an impact driver or back it out by hand with whatever bit is in the pouch.

Sharp point tapping screws need a pilot hole or a thin, soft substrate they can pierce. The QDS171 has a sharp point, not a drill point, so it is intended for pre-punched or pre-drilled holes and light gauge material. If you are fastening straight into heavier steel studs or strut without pre-drilling, you want a self-drilling (TEK style) point instead.

The QDS171 is steel with a zinc plating, which is a mild corrosion coating meant for dry interior work such as panel, box, and strap mounting. For wet, exterior, or coastal exposure, zinc plated steel will rust; use a stainless or hot dip galvanized fastener in those locations.

Order Metallics QDS171. That is the manufacturer part number for the #12 x 1 inch, 5/16 hex head Quadrive sharp point tapping screw in zinc plated steel, and it is the only model on the item. The screws are made in the USA.

That is what it is built for. The QDS171 is an electrical-trade fastener, and the 5/16 hex head lets an electrician drive it with the same nutsetter already in the drill for strap and box work. The #12 by 1 inch size suits shallow attachments where you do not want the point coming through much past the backing.