Metallics JTS17 8 x 3/8 in. Pan Head Phillips Sharp Point Tapping Screws - Steel Zinc - Each

The JTS17 is a Type A tapping screw, meaning a sharp gimlet point with widely spaced threads, 15 threads per inch at a #8 diameter. That geometry is made for thin sheet metal and similar soft, thin sections, where the point pierces and the coarse thread forms its own mating thread without a nut. It is not a machine screw and will not run into a tapped machine thread.

At 3/8 inch of length under a pan head, the JTS17 gives you very little grip, so it suits attaching thin material to thin material, sheet metal brackets, duct flange clips, panel and enclosure work. If you are going through a device or a strap plus the box wall, measure your stack first; anything over about a quarter inch of combined material leaves too few threads engaged and you want a longer screw in the same series.

No. The JTS17 is not Buy American compliant and is not ARRA compliant, with multiple countries of origin. If your contract carries a domestic sourcing clause, these will not satisfy it and you need a domestically produced fastener instead.

A #2 Phillips. The recess is 0.169 to 0.182 inch in diameter and 0.108 inch deep, so a #1 bit will cam out and a #3 will not seat. Keep a sharp #2 in the gun; the screw is rated to a 39 lb-in minimum torsional strength, which is where it twists off if you lean on an impact driver.

These are carbon steel screws with a zinc plated finish, made from AISI 1016 to 1024 steel. Zinc plating handles dry interior and protected locations fine. For sustained outdoor exposure, washdown, coastal air, or anywhere corrosion is a concern, specify stainless rather than zinc plated steel.

Case hardness runs Rockwell C28 to 38, which is what lets the gimlet point pierce and form threads in sheet steel rather than deform. Pair that with the 39 lb-in minimum torsional rating: drive it with a clutched driver, not full impact, and the screw taps cleanly. Thick structural steel is beyond a Type A screw regardless of hardness; that calls for a drilled and tapped hole or a self-drilling screw.

Head and recess dimensions follow ASME B18.6.3-2013, and the thread form follows ASME B18.6.4, the tapping screw standard. One caveat worth noting across the JTS line: dimensions for #9 diameter screws fall outside ASME B18.6.4. The #8 covered here is within the standard.

The JTS17 ships in a jar of 100 pieces, which is the order minimum, at roughly 0.32 lbs per jar. Other sizes and quantities in the series are available by request, so if you are standardizing a truck stock or an MRO bin on several lengths, order against the series rather than piece by piece.

Metallics lists the field application as the electrical, plumbing, heating and air conditioning industries. It is a general sheet metal tapping screw, so duct and hanger work, plumbing strap and bracket attachment, and panel and enclosure assembly all use the same #8 x 3/8 inch pan head Phillips.