Metallics JTTS37 12 x 2 in. Pan Head Tri-Drive Tapping Screws - Steel Zinc - Each

Take your pick. The JTTS37 pan head carries a tri-drive recess, meaning it accepts a slotted bit, a Phillips bit, or a square drive. Handy on a panel job where you are already holding a #2 Phillips or a square drive bit and do not want to swap.

They are a #12 diameter screw, 2 inches long. That is a fairly heavy self-tapping sheet metal screw size, long enough to pass through a box or strut flange and bite well into the substrate.

The JTTS37 is zinc plated steel, which is a mild corrosion coating meant for dry indoor use. For wet, exterior, or washdown locations, specify a stainless fastener instead; zinc plating will eventually rust through in standing moisture.

A pan head sits low with a flat underside and a rounded crown, so it seats clean against sheet metal without the wider bearing surface of a hex washer head. That keeps the fastener from fouling a cover, a knockout, or an adjacent conduit run. The tradeoff is less clamp area, so for thin or oversized holes a washer head or a separate flat washer holds better. The JTTS37 is the pan head version.

It is a tapping screw, so it cuts its own thread in sheet metal and light gauge material once a pilot hole is present. In sheet steel or an existing knockout you can typically drive it direct; in thicker stock, drill a pilot sized to the screw's root diameter so the #12 thread forms properly instead of snapping the screw.