Metallics TXV145D 1/4-28 x 5 in. 5/16 Hex Head Heavy Duty Drill Screws - #5 Drill Point - All-Weather - Each

The Metallics TXV145D is a Type BSD heavy duty drill screw with a #5 drill point, which is the heaviest point in the self-drilling range and is meant for steel-to-steel work rather than light gauge sheet. Metallics calls it out for heavy duty steel-to-steel application. At 5 inches of overall length with a 1/4-28 thread, it is intended for stacked or thick steel members where a standard #2 or #3 point screw would stall out.

Country of origin is the United States, but Metallics lists the TXV145D as not Buy American compliant and not ARRA compliant. If your project carries either requirement in the specs, the domestic origin alone will not satisfy it, so plan on a fastener that is certified to that clause.

Use a 5/16 inch hex driver. The head is a hex washer head with hex drive, and the catalogued head width runs 0.367 to 0.375 in. with a width across corners of 0.409 in., so a 5/16 magnetic nutsetter in an impact or screwgun seats it correctly.

The TXV145D carries a zinc all-weather coating, which is what Metallics specifies for exposed and weather-facing steel-to-steel fastening. It is a coated carbon steel screw, not stainless, so for direct saltwater exposure or submerged conditions you would want a stainless fastener instead.

Case hardness is Rockwell C32-40 with a minimum torsional strength of 150 lb-in. That is the spec to check against your driver: keep an impact driver's torque below that figure and let the point do the drilling rather than forcing it, and the screw will drill and tap without shearing. Steel is AISI 1016-1024.

Threads are 28 per inch on a 1/4 inch diameter, which is the 1/4-28 UNF fine series, made to SAE J78-2013 for thread rolling screws. A standard 1/4-28 fine nut will run on the threads. Do not confuse it with the coarse 1/4-20 that most general construction screws use.

No. The TXV145D is a drill point screw, so the point drills and the thread taps in one pass with no pilot hole. The only prep you need is a square, well-clamped joint so the two steel members stay tight while the point cuts through.

These ship in a jar, and the order minimum is 50 each. Other sizes and quantities in the TXV series are available by request if 5 inches is longer than your connection needs.

Head geometry is built to ASME B18.6.3-2010, with a head height of 0.172 to 0.19 in. That matters where the fastener sits under a bracket, clip, or strut fitting and you need the head profile to clear. Spec writers asking for a B18.6.3 tapping screw head will accept this one.