Metallics TSP28M 10 x 1 in. Pan Head Phillips Sharp Point Tapping Screws - Steel Zinc - Each

The pan head measures 0.357 to 0.373 inch across and 0.122 to 0.133 inch high. That is useful if you are fastening through a knockout, a slotted strap, or a bracket hole: the head needs a bearing surface narrower than 0.357 inch to pull down on, and it will stand roughly an eighth of an inch above the surface. If you need the head flush with the material, a pan head will not do it.

No. The TSP28M ships as a jar of 1,000 with a 1,000 piece order minimum, so that is the smallest buy on this part number. Metallics does make other sizes and quantities in the sharp point tapping screw line by request.

No. These screws are not Buy American compliant and not ARRA compliant, with multiple countries of origin. On a federally funded project with domestic sourcing requirements you will need a documented domestic fastener instead.

The Metallics TSP28M is a Type A tapping screw, meaning it has a gimlet (sharp) point and a coarse 12 threads per inch thread that cuts its own thread as it drives. That combination is made for thin sheet metal work, the kind of thing you do hanging boxes, straps, and sheet metal brackets without pre-tapping. Thread form follows ASME B18.6.4 and the head geometry follows ASME B18.6.3-2013. If you need a screw that drills its own pilot hole in heavier gauge, a Type A sharp point is the wrong choice; a self-drilling point screw is.

A #2 Phillips bit. The recess is 0.186 to 0.199 inch in diameter, 0.124 inch deep, with a 0.031 inch slot width, so a #1 bit will cam out and a #3 will not seat. Stock #2 bits if you are running these on an impact or a screwgun.

The TSP28M is rated at 48 lb-in minimum torsional strength and case hardened to Rockwell C28 to 38, made from AISI 1016 to 1024 steel. That is enough for normal sheet metal driving, but an impact driver can easily exceed 48 lb-in once the head seats, so set the clutch or back off the trigger at seating rather than driving to stall.

These are zinc plated steel. Zinc plating is a mild indoor corrosion coating, so it suits dry interior electrical and sheet metal work. For exterior, damp, or coastal exposure, go to a stainless steel or a hot dip galvanized fastener instead.

Fastener length is 1 inch. On a pan head screw that length is measured from the underside of the head to the point, so the overall height off the work surface is the 1 inch shank plus a head standing 0.122 to 0.133 inch proud. Figure your grip accordingly when you are fastening through a strap or bracket into sheet metal.