Metallics DS1745M 12 x 2 in. 5/16 Indented Hex Head Slotted Sharp Point Tapping Screws - Steel Zinc - Each

Type A is a sharp gimlet point tapping screw, meant to be driven into thin sheet metal, and into resin or wood where a coarse thread holds. The Metallics DS1745M is a #12 x 2 inch Type A with 11 threads per inch, so it cuts its own thread as it goes, no tapped hole needed. For thicker steel or a pre-tapped hole you want a blunt point Type B or a thread-cutting type instead.

Either works. The head is an indented hex with a slot cut across it, measuring 0.305 to 0.312 inch across the flats and 0.34 inch across the corners, so a 5/16 socket or nut driver seats on it. The slot is 0.056 to 0.067 inch wide and 0.077 to 0.093 inch deep if you need to finish it with a flat blade in a tight spot.

It ships as a box with a 5,000 piece order minimum, so this is a bulk buy, not a handful. Metallics does produce other sizes and quantities in the same tapping screw line on request if 5,000 of the #12 x 2 inch is more than the job needs.

No. These are not Buy American compliant and not ARRA compliant, with country of origin listed as multiple. If your government, school, or transit job carries a domestic sourcing clause, this part will not clear it and you need a domestically produced tapping screw.

Head height runs 0.139 to 0.155 inch, and the integral washer under the head is 0.398 to 0.432 inch in outside diameter with a thickness of 0.022 to 0.039 inch. That washer face spreads the load on sheet metal and gives you a wider bearing surface than a plain hex head, which matters when you are pulling down straps or thin gauge panel.

The DS1745M is carbon steel with a zinc plating, which handles indoor and sheltered damp conditions but is not a marine or sustained-wet finish. For exterior exposure, roof work, or treated lumber contact, step up to stainless or a hot dip galvanized fastener.

Minimum torsional strength is 83 lb-in, with the steel case hardened to Rockwell C28-38 and made from AISI 1016 to 1024 carbon steel. That is enough to cut thread in sheet metal, but 83 lb-in is a snapping threshold, not a target, so a high torque impact will shear heads if you do not back the clutch off.

Yes. Head dimensions follow ASME B18.6.3-2010 and the thread form follows ASME B18.6.4. One caveat worth knowing: dimensions for #9 diameter screws in this Metallics tapping screw line fall outside ASME B18.6.4, though that does not affect the #12 size.

At 2 inches of length with an 11 TPI coarse Type A thread and a sharp gimlet point, the DS1745M is sized for anchoring boxes, straps, and brackets through sheathing or sheet into framing, which is why Metallics lists it as an electrical fastener. Thread engagement is what holds, so leave enough material behind the panel for the point to bite rather than counting on the full 2 inches.