Metallics JQK19V 8 x 2 in. 1/4 Hex Head Slotted Sharp Point Self-Piercing & Tapping Screws - Steel Zinc - Each

No pre-drilling. The JQK19V is a sharp point self-piercing and tapping screw, so it pierces thin sheet metal and cuts its own thread as it drives. Twin lead threads keep the driving torque down. For thicker steel or structural material you want a drill-point screw instead.

A 1/4 inch hex socket or nut driver fits the head, measured at 0.244 to 0.25 inch across. The head also carries a slot, 0.045 to 0.054 inch wide and 0.052 to 0.074 inch deep, so a flat blade works for hand starting or final snugging in tight spots where a socket will not sit square.

Metallics lists the JQK19V as both Buy American compliant and ARRA compliant, which is what a public-works or federally funded spec usually asks for. Country of origin is recorded as multiple, so if your contract requires a single named origin on the submittal, that is the detail to pin down.

It is a #8 diameter, 2 inch long screw with 15 threads per inch. The 2 inch length gives you plenty of reach for strapping, bracket, or box work over thin-gauge metal, and the undercut area under the head lets more of that thread engage the material.

Yes, there is an integral washer 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. Head height runs 0.096 to 0.11 inch. That washer face spreads the load on sheet metal and helps keep the head from pulling through thin stock.

These ship 500 to a jar, and 500 count is the order minimum. The jar itself runs 4.5 in. wide, 4.5 in. long, 7.25 in. tall and weighs 4.4 lbs, so plan a shelf slot for it on the truck. Metallics does offer other sizes and quantities in this family by request.

The JQK19V is carbon steel with a zinc finish, which suits dry interior electrical work, inside boxes, enclosures, panel rooms, and ceiling spaces. Zinc plating is not a marine or sustained wet-location coating, so for exterior exposure or wash-down areas step up to a stainless or hot-dip galvanized fastener.

Use them as a guide, not as a hard gauge. Self-piercing screw heads do not match standard tapping screw heads, and there is no single industry standard for self-piercing dimensions, so the 0.244 to 0.25 inch hex width and 0.096 to 0.11 inch head height are ranges that may deviate. If the head has to clear a tight knockout or seat in a counterbore, check against the actual part.

Material is AISI 1018 to 1022 carbon steel, case hardened to Rockwell C28-38. That hardness is enough for the point to pierce and tap thin-gauge sheet without the thread rolling over, while keeping the screw from being brittle at the head.