Metallics JDS163V 6 x 1 in. 1/4 Indented Hex Head Slotted Sharp Point Tapping Screws - Steel Zinc - Each

Either works. The JDS163V has an indented hex head measuring 0.244 to 0.25 inch across the flats, so a standard 1/4 inch hex driver or nut setter seats on it, and the head is also slotted (slot width 0.039 to 0.048 inch, depth 0.033 to 0.046 inch) if you need to finish by hand in a tight spot. Width across corners is 0.272 inch, which is what matters if you are driving inside a shallow box or recess.

The JDS163V is a Type A tapping screw with a gimlet (sharp) point, which means it needs a pilot hole in sheet metal but will start on its own in softer material. It cuts its own thread as it goes at 18 threads per inch. If you are going into thicker gauge steel with no pre-punched hole, you want a self-drilling (Type TEK) screw instead, because a gimlet point will not drill through metal.

Yes, the head carries a washer face with an outside diameter of 0.302 to 0.328 inch and a thickness of 0.015 to 0.025 inch. Head height runs 0.08 to 0.093 inch. That bearing surface spreads load on thin sheet and keeps the head from pulling through, but it is not a sealing washer, so it is not a weatherproofing solution.

Torsional strength on the JDS163V is 24 lb-in minimum, with case hardness at Rockwell C28-38 and steel to AISI 1016-1024. That is the rated twist limit for a #6, and it is easy to exceed with an impact driver on a tight hole. Use a clutched screwgun or a nut setter on a drill and back off the torque, especially in heavier gauge.

Material is steel with a zinc finish, which is a general-purpose indoor and protected coating. It handles interior electrical work, panel and enclosure fastening, and damp but covered areas. For sustained outdoor exposure, washdown, or coastal conditions, move to stainless or a hot-dip galvanized fastener instead, since plain zinc plating will eventually show red rust.

They ship in a jar of 500 count, and 500 is the order minimum. Figure the shipping unit at about 2.15 lbs.

The JDS163V is flagged both ARRA compliant and Buy American compliant, which is what a government, school, or healthcare procurement file usually needs on a fastener line item. Country of origin is listed as multiple, so if your spec requires a single named origin on the submittal, that is the detail to pin down before you standardize on it.

Head and body dimensions follow ASME B18.6.3-2010, and the threads follow ASME B18.6.4. Steel is to AISI 1016-1024. One caveat worth knowing if you are matching a family of these across sizes: dimensions for the #9 diameter fall outside ASME B18.6.4.