Metallics QK25M 10 x 3/4 in. 1/4 Hex Head Slotted Sharp Point Self-Piercing & Tapping Screws - Steel Zinc - Each

No pilot hole needed. The QK25M is a sharp point self-piercing and tapping screw, so it pierces and forms its own thread in sheet metal as you drive it. Twin lead threads cut the driving torque, and the undercut under the head gives you more thread engagement in the material.

Yes, that is exactly what the QK25M is built for. Metallics lists it for the electrical, plumbing, heating and air conditioning trades, which is the standard self-piercing screw used on duct seams, box mounting and strap work. At 3/4 inch long with a #10 diameter and 12 threads per inch, it suits light-gauge sheet metal where you want the fastener to make its own hole.

Not necessarily. Head dimensions on self-piercing screws differ from those of standard tapping screws, and there is no single industry standard for self-piercing screw dimensions, so Metallics publishes its figures as a guide with possible deviation. If you are matching an existing hole pattern or a slotted bracket, check the 0.244 to 0.25 inch head width against what you have rather than assuming it drops in.

No. These are not Buy American compliant and not ARRA compliant, with country of origin listed as multiple. On a federally funded or domestic-preference spec job you will need a domestically produced fastener instead.

The washer OD runs 0.384 to 0.414 inch with a washer thickness of 0.019 to 0.031 inch. Head width is 0.244 to 0.25 inch across the hex with a head height of 0.096 to 0.11 inch. That washer face bridges a little slop but is not a sealing washer, so for a torn or stretched hole you want a larger separate washer under the head.

They are case hardened to Rockwell C28-38 and made from AISI 1018-1022 steel, which is the normal spec for a self-piercing screw driven into light-gauge sheet. That hardness lets the sharp point pierce without rolling over, while the carbon steel core keeps enough ductility that heads do not pop off at normal driving torque.

The QK25M is steel with a zinc finish. Zinc plating handles indoor and protected mechanical spaces, duct chases and panel work fine, but it is not a stainless or coated exterior fastener. For direct weather exposure, roof curbs or coastal air, specify a stainless or exterior-coated self-piercing screw instead.

They ship 1,000 to a jar, and 1,000 is the order minimum. Total package weight is 4.56 lbs. If you need a different size or a different count, Metallics offers other sizes and quantities on request.