Metallics JDS81V 10 x 3 in. 5/16 Indented Hex Head Slotted Sharp Point Tapping Screws - Steel Zinc - Each

Type A is a thread-forming screw with a gimlet (sharp) point. It cuts its own thread in a pre-punched or pre-drilled hole in thin sheet metal, and it will start in wood or soft materials, but it does not drill its own pilot in heavier gauge steel. For that you want a self-drilling (Type TEK) screw. The JDS81V runs 12 threads per inch on a #10 diameter at 3 inches long, so it is a coarse-thread screw meant for thin stock and soft substrates rather than structural steel.

The JDS81V is flagged compliant for both Buy American and ARRA. Country of origin is listed as multiple, so if your specification demands documented origin on a specific lot, request the certification with the order.

The head is an indented hex with an integral washer face, 0.384 to 0.414 inches outside diameter and 0.019 to 0.031 inches thick. Head height is 0.105 to 0.12 inches. That washer face spreads the load and seats flat, so you don't need a separate finish washer for sheet metal or box mounting.

The JDS81V ships as a 500 count jar, and 500 is the order minimum. It is not sold loose by the piece. Other sizes and quantities in the JDS line are available by request.

Zinc plating over carbon steel gives light corrosion protection, which suits dry interior electrical work, panel and box mounting, and sheltered applications. For sustained exterior exposure, washdown areas, or coastal sites, specify stainless or a hot dip galvanized fastener instead; zinc plate will eventually bloom and rust in those conditions. The base steel here is AISI 1016 to 1024.

Head and body dimensions follow ASME B18.6.3-2010, and the thread conforms to ASME B18.6.4. Torsional strength is 48 lb-in minimum with a case hardness of Rockwell C28-38. One caveat worth knowing across the JDS series: dimensions for #9 diameter screws fall outside ASME B18.6.4.

At 3 inches of overall length on a #10 shank, the JDS81V has the reach to pass through strapping, drywall, or a mounting flange and still get good thread engagement behind it. It is a tapping screw, though, not a masonry anchor, so into concrete or block it needs a plastic or lead anchor set in a drilled hole. The gimlet point will start in wood or thin metal without one.

A full 500 count jar comes to 9.05 lbs. Jar footprint is listed at 3 inches length and width with a 2.15 inch height, so it stores upright in a standard parts bin.