Metallics TS25B 10 x 1/2 in. Pan Head Phillips Sharp Point Tapping Screws - Steel Zinc - Each

The TS25B is a #10 x 1/2 inch Type A tapping screw with a gimlet (sharp) point. The gimlet point and 12 threads per inch are the classic sheet metal combination: it pierces and taps its own thread in thin sheet steel, electrical boxes, duct, and light-gauge metal without a pilot hole in most cases. It is not a machine screw, so it does not take a nut-and-thread fit, and it is not a self-drilling screw with a drill flute, so heavy gauge steel still wants a pilot hole.

Yes on both counts. The TS25B is flagged Buy American compliant and ARRA compliant, which is what a government, school, or institutional spec usually asks for on fasteners. Country of origin is listed as multiple, so if your submittal requires a single named origin, note that the material standard, AISI 1016 to 1024, and the dimensional standard, ASME B18.6.3-2013, are the figures that will go on the sheet.

The TS25B gives you 1/2 inch of overall screw length under a pan head, so the usable thread engagement after the material you are clamping is short. It suits stacking thin sheet to thin sheet, strap and clip attachment, cover plates, and box mounting. If you are going through insulation, a spacer, or anything more than light gauge sheet, the point will bottom out before it taps enough thread, and you want a longer screw in the same #10 Type A pattern.

A #2 Phillips bit. The recess is cut to a 0.186 to 0.199 inch diameter, 0.124 inch deep, with a 0.031 inch recess width, which is standard #2 Phillips geometry. A #1 bit will cam out and chew the recess; a #3 will not seat.

They are rated at 48 lb-in minimum torsional strength and heat treated to Rockwell C28 to 38, so the shank takes real drive torque. That said, 48 lb-in is a minimum spec, not an impact-gun allowance: a clutch-set screw gun or a driver dialed back keeps you inside it. Running them hard into heavy steel is how you twist off a #10.

The TS25B is carbon steel with a zinc finish, which is an indoor and dry-location coating. Zinc plating gives you handling and light humidity protection, not weather exposure, so for exterior, wet, or corrosive locations step up to stainless steel or a hot dip galvanized fastener rather than zinc plated steel.

Head and recess dimensions follow ASME B18.6.3-2013, and the thread form follows ASME B18.6.4, which is the tapping screw thread standard. Material is AISI 1016 to 1024 carbon steel. If a drawing calls for a B18.6.4 Type A sheet metal screw in #10, these match on both the thread and the head geometry.

They ship boxed, with an order minimum of 10,000 pieces (one thousand count unit of measure). Total box weight is listed at 47.82 lbs. That makes the TS25B a stocking buy for a shop or an MRO crib rather than a handful for one device box.