Metallics JQK17W 8 x 1-1/2 in. 1/4 Hex Head Slotted Sharp Point Self-Piercing & Tapping Screws - Gray - Steel Zinc - Each

No pre-drill. The JQK17W 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 once seated. It is an 8 diameter by 1-1/2 inch screw with 15 threads per inch.

Either works. The head is a 1/4 hex with a slot cut into it, so you can run it with a 1/4 inch hex nutsetter in a drill or finish it by hand with a flat blade. Head width measures 0.244 to 0.25 in., head height 0.096 to 0.11 in., and the slot is 0.045 to 0.054 wide by 0.052 to 0.074 deep.

Yes, it has an integral washer face: outside diameter 0.322 to 0.348 in. with a washer thickness of 0.019 to 0.031 in. That bearing surface is what spreads load on thin sheet metal, so no separate washer is needed for typical electrical box and sheet metal work.

They ship in a jar, with a minimum order of 100 count. Package weight is 0.71 lbs. Other sizes and quantities are available by request.

Steel with a zinc finish, made from AISI 1018 to 1022 steel and case hardened to Rockwell C28-38 so the point can tap its own thread. Zinc plating is a standard indoor corrosion coating. For sustained wet or exterior exposure, step up to a hot dip galvanized or stainless fastener instead.

The JQK17W is flagged both ARRA compliant and Buy American compliant in the manufacturer record, with country of origin listed as China. Procurement officers should take the compliance flags as the vendor's declaration and match them against the specific clause on the contract.

Because self-piercing screws are not dimensioned the same way. Metallics states 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 values (0.244 to 0.25 in. head width, 0.096 to 0.11 in. head height) are a guide and deviations can occur. If a drawing calls out a hard head dimension tolerance, don't assume this screw holds it.

At 1-1/2 inches the JQK17W is one of the longer self-piercing sizes, meant for runs where you have to reach through furring, strap, or stacked sheet before the point engages. If you are only fastening two layers of thin sheet, a shorter 8 diameter self-piercing screw is the cleaner choice so you aren't leaving an inch of thread hanging behind the panel. Thread pitch here is 15 per inch.