Metallics JTSS25SS 10 x 1/2 in. Pan Head Square Drive Tapping Screws - 18-8 Stainless - Each

A #2 square (Robertson) bit. The recess is specified as driver size 2R, with 0.112 inch across the flats and a gaging depth of 0.060 to 0.075 inch, so a worn or undersized bit will cam out. Carry a fresh #2 square bit if you are running a jar of 100.

You can, but watch the corrosion. These are 18-8 stainless screws, and fastening stainless parts to aluminum or steel can set up a galvanic couple in some environments. Indoors and dry it is rarely an issue; in wet, coastal, or wash-down locations expect attack on the aluminum or steel, not the screw. Isolate or choose a matching-metal fastener in those spots.

They are Type A tapping screws with a gimlet point, so the point starts in sheet metal and the 12 threads-per-inch coarse thread forms its own mating thread as it drives. A pilot hole is still the norm in thicker gauge or in hard material to keep from stripping the recess at the 48 lb-in minimum torsional rating.

No. The JTSS25SS is not Buy American compliant and is not ARRA compliant, and country of origin is listed as multiple. If your project has domestic-sourcing requirements, this fastener will not satisfy them.

The JTSS25SS is a 10 x 1/2 inch screw, so after the head and the gimlet point you have only a short run of thread. It suits attaching a device, strap, or cover to sheet metal, a box, or thin stock. For wood blocking, thicker substrates, or anything needing real pull-out, step up to a longer length.

Head dimensions follow ASME B18.6.3-2013 and the thread follows ASME B18.6.4. That matters on a submittal where a spec calls out standard-conformance fasteners rather than a brand name.

They ship in a jar of 100, which is the order minimum. The jar measures 3 in by 3 in by 2.15 in and weighs 0.52 lbs, so it fits a van bin or a tool bag pocket easily.

It is stocked for the electrical, plumbing, heating and air conditioning trades, the sort of screw used for hanging straps, attaching plates and covers, and sheet metal work where the stainless matters more than the strength. The square recess is the reason mechanical crews like it: the bit stays seated overhead where a Phillips would cam out.

Other sizes and quantities of the JTSS series pan head square drive tapping screws are available by request. The JTSS25SS itself is the 10 x 1/2 inch, 18-8 stainless version in a 100-count jar.