Metallics JSTSP26 12 x 1/2 in. Pan Head Phillips Tapping Screws - 18-8 Stainless - Each

Be careful. The 18-8 stainless JSTSP26 screw into aluminum or steel can set up a galvanic couple in some environments, which corrodes the softer base metal around the fastener. Outdoors, in wash-down areas or anywhere salt is present, that matters. Where the base metal is aluminum and the environment is wet, isolate the joint or use a fastener matched to the base metal instead.

No. The JSTSP26 is not Buy American compliant and is not ARRA compliant, and country of origin is listed as multiple. On a federally funded project with domestic-sourcing language in the spec, these will not pass, so source a domestically manufactured fastener for that work.

A #3 Phillips bit. The recess on the JSTSP26 is 0.246 to 0.259 in. across, 0.141 in. deep and 0.034 in. wide at the slot, which is a #3 recess. Dropping to a #2 bit in this size is the usual cause of cam-out and stripped heads in stainless, since stainless galls rather than shearing cleanly.

The JSTSP26 is rated to 83 lb-in minimum torsional strength, so it has a defined twist-off limit. Stainless has lower torsional strength than hardened carbon steel screws of the same size, so set a clutch or use a drill on a moderate setting rather than an impact driver at full output, especially in the last turn when the head seats.

They come in a jar, and the minimum order is one jar of 100 pieces. So a single purchase of the JSTSP26 gets you 100 screws, not a loose count. The jar weighs 0.49 lbs.

At 1/2 inch overall, the JSTSP26 gives you very little thread past the material, so it suits thin gauge work where the screw only has to engage one or two sheets. If you are going through insulation, a spacer, a strap plus a stud, or anything that eats depth before the screw reaches holding metal, step up to a longer length in the same JSTSP series. Metallics lists other sizes and quantities in this series.