Metallics JDS155V 10 x 1/2 in. 1/4 Indented Hex Head Slotted Sharp Point Tapping Screws - Steel Zinc - Each

This is a Type A tapping screw with a gimlet (sharp) point, so it threads itself into an existing pilot hole or a punched hole in thin sheet metal. It does not drill its own hole. If you're fastening into pre-punched enclosure knockouts, box brackets, or thin-gauge metal, the sharp point starts cleanly. For unpunched or heavier stock you want a self-drilling (Type TEK) screw instead. The thread is 12 per inch per ASME B18.6.4, which is the coarse Type A pitch for sheet metal.

Metallics lists the JDS155V as both ARRA compliant and Buy American compliant. Country of origin is recorded as multiple, so if your contract requires a single named country of manufacture on the submittal, get the origin confirmed for the specific lot before you submit.

Dimensions are to ASME B18.6.3-2010 and the thread form to ASME B18.6.4. Steel is AISI 1016 to 1024, case hardened to Rockwell C28-38, with a minimum torsional strength of 48 lb-in. One caveat Metallics states: dimensions for the #9 diameter fall outside ASME B18.6.4. This is a #10, so the standard applies.

With 1/2 inch of overall length under an indented hex washer head, the usable grip is short, which is why these are used on sheet metal, strap, straps-to-box, and bracket work rather than anything thick. Type A threads need two or three threads engaged past the back of the material to hold, so figure on stacked sheet thicknesses well under 1/4 inch total. For deeper stack-ups, step up to a longer screw in the same series.

No separate washer. The JDS155V head is an indented hex washer style with an integral washer face 0.384 to 0.414 inch outside diameter and 0.019 to 0.031 inch thick, so it spreads load on sheet metal on its own. Overall head height is 0.105 to 0.12 inch, low enough that it won't foul a cover plate sitting over it.

They ship 500 to a jar, and 500 count is the order minimum. The jar weighs 1.85 lbs. Metallics notes other sizes and counts are available by request if 500 of this size isn't what the job needs.

The JDS155V is carbon steel with a zinc plating, which is a mild indoor and protected-location finish. It's fine in dry interior work, panel and enclosure assembly, and normally dry mechanical spaces. For direct weather exposure, wet locations, or coastal air, specify stainless or a hot-dip/mechanically galvanized fastener instead, because zinc plating is thin and will rust once it's breached.

Minimum torsional strength is 48 lb-in, which is the figure that tells you how much twist the screw takes before it shears. That's modest, so a high-torque impact driver on full setting will snap #10 tapping screws in sheet metal. Use a clutched screw gun or an impact on its lowest setting and stop once the washer face seats.