Metallics TXV143D 1/4-28 x 3 in. 5/16 Hex Head Heavy Duty Drill Screws - #5 Drill Point - All-Weather - Each

The #5 point is the heaviest drill point in the Metallics TXV line and is meant for heavy steel-to-steel work, which is why this screw runs a 1/4-28 thread and a 3 inch length. The point drills the hole, taps the thread, and fastens in one pass, so no pre-drilling. Practically, the length has to cover your drill point plus the combined steel you are going through and still leave thread engagement, so measure your stack before you commit to the 3 inch.

Fine thread is the correct choice into steel. At 28 threads per inch, the 1/4-28 bites into metal with more threads engaged per inch of grip, which is what you want in a steel-to-steel joint. Coarse thread screws are for wood and sheet materials, not structural steel. The thread conforms to SAE J78-2013 for self-drilling tapping screws.

No. The TXV143D is made in the United States and its country of origin is listed as United States, but it is flagged as not Buy American compliant and not ARRA compliant. If your specification requires either certification, this is not the fastener to submit.

A 5/16 hex socket or nut setter. It is a hex washer head with hex drive, head width 0.367 to 0.375 in. and head height 0.172 to 0.19 in., with an integral washer measuring 0.480 to 0.520 in. outside diameter and 0.030 to 0.050 in. thick. Width across corners is 0.409 in., so a standard 5/16 magnetic nut setter seats it without cam-out.

Yes. The TXV143D carries a zinc plus all-weather coating, which is what Metallics puts on fasteners intended for exposed and damp service. For direct saltwater exposure or dissimilar-metal contact, a stainless fastener is the better call.

The TXV143D is case hardened to Rockwell C32-40 with a 150 lb-in minimum torsional strength, so it is built to take drilling torque in steel. Even so, drive with a clutch-controlled driver rather than a full-power impact and back off as soon as the washer seats. Overdriving past seating is what breaks heads on any self-drilling screw.

Steel per AISI 1016-1024, with head dimensions to ASME B18.6.3-2010 and threads to SAE J78-2013. That combination is what a spec writer looks for on a self-drilling tapping screw submittal, so the Type BSD designation and those three callouts are the ones to put on the paperwork.

They come in a jar, with a 50 each order minimum. Metallics lists other sizes and quantities in the TXV series by request if 3 inch or 50 pieces is not what the job needs.