Metallics QK19WM 8 x 2 in. 1/4 Hex Head Slotted Sharp Point Self-Piercing & Tapping Screws - Gray - Steel Zinc - Each

No. The QK19WM is a sharp point self-piercing and tapping screw, so it pierces thin sheet and forms its own thread as it drives. Twin lead threads cut the driving torque. For heavier gauge or structural steel you want a drilled pilot or a self-drilling point screw instead, since a sharp point will walk and stall rather than cut through.

Not exactly. 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 figures are a guide and small deviations happen. If a cover plate or clip has a tight head pocket, check it against the 0.244 to 0.25 inch hex width and 0.096 to 0.11 inch head height before committing to 1,000 pieces.

The QK19WM takes a 1/4 inch hex driver. Head width measures 0.244 to 0.25 inch across the flats, with a head height of 0.096 to 0.11 inch. It also has a slotted drive cut into the hex head (slot width 0.045 to 0.054 inch, depth 0.052 to 0.074 inch), so you can back it out with a flat blade if you cannot get a socket on it in tight work.

The QK19WM is a #8 diameter, 2 inch long screw with 15 threads per inch, so it has plenty of shank to pass through a bracket or strap and still get solid thread engagement in the substrate. The undercut area beneath the head adds usable thread length rather than wasting it under the washer. Typical use is fastening boxes, straps, and hangers into light sheet metal or wood framing where 2 inches of reach is needed.

It is a zinc plated carbon steel screw. Zinc plating handles indoor and protected conditions well, including mechanical rooms and damp basements, but it is not a stainless or hot dip galvanized fastener. For direct exposure to weather, pressure treated lumber, or coastal air, step up to stainless.

There is an integral washer head on the QK19WM, with a washer outside diameter of 0.322 to 0.348 inch and washer thickness of 0.019 to 0.031 inch. That is a bearing washer that spreads load on thin sheet, not a rubber or EPDM sealing washer, so it does not weatherproof the hole.

The QK19WM ships as a box with an order minimum of 1,000 pieces (one thousand count unit). Box weight is 8.9 lbs. Other sizes and quantities can be had by request if 1,000 of this length is not what the job needs.

Country of origin on the QK19WM is listed as multiple, so it is not a single-source domestic fastener and should not be submitted as a Buy American or ARRA domestic line item. For a federally funded job with domestic content requirements, specify a fastener documented as domestically produced.

Case hardness runs Rockwell C28-38, from AISI 1018 to 1022 low carbon steel. That is hard enough to form threads in sheet metal while keeping the shank ductile rather than brittle, which is why these drive without snapping heads at normal gun speeds.

They are stocked for the electrical, plumbing, and heating and air conditioning trades. On the job that means strapping conduit and pipe, hanging boxes and panels to light sheet metal studs, and securing duct accessories where you want a 1/4 inch hex you can run with a drill rather than a screwdriver.