S.Drilling Screw - Nut-Head (1-inch)

Cavalry self-drilling screws, one inch long, with a hex nut head. The head is the difference from the star-head version: a hex head is driven with a nut setter rather than a bit, and it will not cam out under torque no matter how hard the screw fights, which is why it is the head roofers choose for driving hundreds of fixings into purlins in a day. The point drills its own hole through the steel and cuts its own thread in one action, so nothing is pre-drilled. Used on iron sheet roofing, steel framing, cladding, gutter and fascia brackets and ducting. Drive at moderate speed, let the point cut before applying pressure, and stop when the head seats - running on crushes any washer and dimples the sheet.