Metallics JDS151V 7 x 1/2 in. 1/4 Indented Hex Head Slotted Sharp Point Tapping Screws - Steel Zinc - Each

The JDS151V has an indented hex head measuring 0.244 to 0.25 inch across the flats, so a 1/4 inch hex driver or nut setter is the right tool. It also has a slot in the head (0.039 to 0.048 inch wide, 0.04 to 0.054 inch deep), so a small flat blade will turn it if you need to back one out by hand in a tight spot. Width across corners is 0.272 inch.

The JDS151V is flagged compliant for both Buy American and ARRA, which is what a government, school district or transit procurement officer is checking for. Country of origin is listed as multiple, so if your specification requires documentation of a single origin, request the certification for the lot you are buying.

Head and body dimensions follow ASME B18.6.3-2010 and the thread follows ASME B18.6.4. Material is AISI 1016 to 1024 carbon steel, case hardness is Rockwell C28-38, and minimum torsional strength is 30 lb-in. If your submittal calls out a B18.6.4 tapping screw, this meets it.

This is a Type A tapping screw with a gimlet (sharp) point, which is the classic point for thin sheet metal, resinous plywood and asbestos-cement type board. The sharp point lets it start in light gauge material without a drilled hole in many cases. For thicker steel, a Type B blunt point or a self-drilling point is the better choice, because a Type A thread is coarse (16 threads per inch here) and meant for thin stock.

Yes, the head has an integral washer face. Washer outside diameter runs 0.302 to 0.328 inch and washer thickness 0.017 to 0.029 inch, which gives you a slightly wider bearing surface than the 1/4 inch hex itself without adding a loose washer to the job.

The JDS151V is carbon steel with a zinc finish, which is fine for dry interior work, panel boxes, strut and general indoor electrical rough-in. Zinc plating gives limited corrosion protection, so for exterior exposure, wet locations or coastal air you want a stainless or hot dip galvanized fastener instead.

At 1/2 inch of length with a 16 TPI coarse thread, the JDS151V gives you a short reach, which is what you want when there is a conductor or an energized component behind the sheet. Head height is only 0.08 to 0.093 inch, so it sits nearly flush and does not foul a cover plate or an adjacent device.

The JDS151V itself is one configuration: #7 diameter, 1/2 inch long, indented hex head, zinc plated steel. Other sizes and quantities in the JDS series of indented hex head slotted tapping screws are available by request, so if you need a #8 or #10, or a longer screw for a thicker build-up, ask for the matching JDS part rather than mixing head styles across the job.

A #7 sits between the common #6 and #8, so measure before you assume a match. Note that on this product family, dimensions for the #9 diameter are called out as independent of ASME B18.6.4, which is worth knowing if you are standardizing a parts bin across several diameters. The #7 x 1/2 in. JDS151V follows ASME B18.6.3-2010 for its head and B18.6.4 for its thread.