Metallics QK175M 8 x 1-1/2 in. 1/4 Hex Head Slotted Sharp Point Self-Piercing & Tapping Screws - Steel Zinc - Each

No. The QK175M is a sharp point self-piercing and tapping screw, so it pierces and forms its own thread in sheet metal as it drives. Twin lead threads cut the driving torque, which helps when you are running a lot of them by hand or with a cordless driver.

The head is a 1/4 inch hex with a slotted drive, so either works. A 1/4 inch hex driver or nutsetter is the faster option for volume work; the slot (0.045 to 0.054 inch wide, 0.052 to 0.074 inch deep) lets you finish or back one out with a flat blade when you cannot get a socket in. Measured head width runs 0.244 to 0.25 inch with a head height of 0.096 to 0.11 inch.

Yes. These are case-hardened to Rockwell C28-38, which is what lets a sharp point pierce and tap light gauge sheet steel such as studs, track, and duct without a pilot hole. For thicker structural steel you want a self-drilling point instead of a sharp point.

It comes with an integral washer section under the hex head, with an outside diameter of 0.322 to 0.348 inch and a thickness of 0.019 to 0.031 inch. That gives you bearing surface against sheet metal without stocking separate washers. There is also an undercut beneath the head so more thread engages the material.

The QK175M ships as a box with a 5,000 piece minimum. Metallics does make other sizes and quantities available by request, so if you need a smaller count or a different length in the same JQK sharp point self-piercing line, that is a request rather than a stock pick.

The QK175M is steel with a zinc finish, which is a general indoor and protected-location plating. It handles normal construction and interior electrical work, but for sustained exterior exposure, wet locations, or coastal air you want a stainless or heavier coated fastener instead. Base material is AISI 1018 to 1022 steel.

Threads run 15 per inch over a 1-1/2 inch length in a #8 diameter. With the undercut under the head, nearly the full shank threads into the work, so you have plenty of engagement for fastening through furring, strap, or trim into light gauge steel while still leaving the point clear on the back side.

The QK175M is flagged compliant for both Buy American and ARRA. Country of origin is listed as multiple, so if your contract requires documented origin for each shipment, ask for the cert with the order.

Because self-piercing screw heads are dimensioned differently from standard tapping screws, and there is no single industry standard for self-piercing screw dimensions. The published ranges on the QK175M, head width 0.244 to 0.25 inch and head height 0.096 to 0.11 inch, are a guide and small deviations can occur. If a socket or counterbore clearance is critical, work from the ranges rather than a generic #8 chart.

A full 5,000 piece box weighs 32.95 lbs, with a carton roughly 9 by 9 by 6.13 inches. Worth knowing if you are staging boxes on a cart or sending them up to a floor by hand.