Metallics RWS105B 8 x 1-1/4 in. Round Washer Head Combo Sharp Point Tapping Screws - Steel Zinc - Each

These are steel with a zinc plating, which is an indoor and protected-location finish. Zinc plate handles job site humidity and incidental moisture fine, but it is not a weather or coastal finish. For sustained exterior exposure, wet locations, or treated lumber contact, move to a stainless or hot dip galvanized fastener instead.

Self-tapping, not self-drilling. The point is a sharp piercing point that forms its own thread, not a drill point with cutting flutes. For thicker structural steel where you need the fastener to cut a hole first, you want a self-drilling point instead. For light gauge metal, strap, and wood, the sharp point is what you want.

Either one. The RWS105B has a combo recess that takes both a Phillips bit and a square (Robertson) driver, so whatever is already in your pouch will run it. The square drive holds the bit on the fastener better when you are working overhead or one-handed, which is why most electricians default to it on washer head screws.

No. It is a sharp point tapping screw, so it pierces and forms its own thread in sheet metal, light gauge studs, and wood without a pilot hole. If you are going into heavier steel, a pilot still makes sense, but for the stud and strap work this size is bought for, you drive it straight in.

The RWS105B uses a round washer head, which is an integral flange under the head. It spreads clamp load over a wider footprint so the screw will not pull through thin sheet metal, plates, strap, or a slotted hole, and it gives you a finished bearing surface without adding a loose washer to the assembly. That is why these get used for mounting boxes, straps, and brackets to light framing.

Yes, the RWS105B is US made, which matters if you are working a government, institutional, or federally funded job with domestic sourcing language in the spec.