Metallics JTEKD4SS 10 x 1/2 in. 5/16 Indented Hex Head Self-Drilling & Tapping Screws with Washer - #3 Drill Point - 410 Stainless Steel - Each

No pilot hole. The #3 drill point cuts and taps in one pass, which is the whole point of a Type BSD screw: one tool, one motion, no layout drilling. Hold the screw perpendicular and let the point cut before you add pressure, and keep the material within the 0.110 to 0.175 in. thickness range it is rated for.

At 1/2 in. length, the JTEKD4SS is sized for fastening into or through metal up to 0.175 in. thick, with enough thread left to tap and hold. It is not long enough to pass through two stacked framing members or to pick up structure behind a thick substrate. For strut-to-sheet, panel-to-stud, or bracket-to-metal work at that gauge it is the right length.

410 stainless is a hardenable martensitic stainless, which is what lets this screw be heat treated to Rockwell C38-46 and still drill its own hole. It gives better corrosion resistance than plain carbon steel, so it holds up in damp interiors and sheltered exterior work. For constant salt spray or coastal exposure, 300-series or coated fasteners are the usual choice, since 410 trades some corrosion resistance for the hardness it needs to cut steel.

It takes a 5/16 in. hex driver. The indented hex head measures 0.305 to 0.312 in. across the flats and 0.34 in. across the corners, with head height of 0.105 to 0.12 in. A standard 5/16 magnetic nut setter in an impact or screwgun is all you need.

The washer is integral to the head, no separate part to stock. Outside diameter runs 0.384 to 0.414 in. with a washer thickness of 0.019 to 0.031 in., so it spreads load over sheet metal and resists pull-through without needing a loose washer or a bonded seal.

Minimum torsional strength is 61 lb-in. Minimum torques are the same for stainless and steel self-drill screws, so there is no derating here versus a carbon steel equivalent. Set your impact or clutch below that figure, since 410 stainless at Rockwell C38-46 will shear rather than strip once the washer seats.

Threads are to SAE J78 - 2013 at 16 threads per inch, and head dimensions are to ASME B18.6.3-2010. It is a Type BSD self-drilling and tapping screw. Note that SAE J78 does not cover #7 diameter drill screws, which matters only if you are substituting diameters on the same submittal.

Both the ARRA and Buy American compliance flags on the JTEKD4SS are marked compliant. Country of origin is China, so if your contract language requires domestic melt and manufacture rather than the broader compliance category, confirm which standard your specification is calling for.

They ship in a jar, with a minimum order of 100 count. Other sizes and quantities are available by request if your job needs a different diameter, length, or pack size.