Metallics TXV145 1/4-20 x 5 in. 5/16 Hex Head Heavy Duty Drill Screws - #5 Drill Point - All-Weather - Each

The Metallics TXV145 is a Type BSD heavy duty drill screw with a #5 drill point, built for steel-to-steel work where the combined thickness is heavier than a standard #2 or #3 point can handle. The point drills its own hole, so no pilot is needed, and the 5 inch length lets you pass through standoffs, built-up framing, or stacked members before the threads engage. Hardness runs Rockwell C32-40 on AISI 1016-1024 steel, with 150 lb-in minimum torsional strength so it survives being driven at the torque heavy gauge demands.

No. The TXV145 is not flagged Buy American compliant and is not ARRA compliant, with country of origin listed as multiple. If you are buying for a federally funded job with domestic sourcing requirements, you'll need a fastener certified to that specification instead.

Use a 5/16 hex driver. The head is a hex washer head measuring 0.367 to 0.375 inches across the flats and 0.409 across the corners, with head height of 0.172 to 0.19 inches. A magnetic 5/16 hex nut setter in an impact or a screw gun is the usual way these get driven, since a 5 inch screw in heavy steel needs the torque held square to the work.

It's integral. The TXV145 has a built-in washer under the hex head, 0.480 to 0.520 inches outside diameter and 0.030 to 0.050 inches thick, so you get bearing surface without stacking a loose washer on the job. For sheet or thin plate that integral flange spreads the clamp load; if you are fastening something with an oversized hole, you'll still want a separate load-spreading washer.

Yes. The TXV145 carries a zinc plus all-weather coating, which is what Metallics specifies for exposed steel-to-steel fastening rather than bare zinc alone. That covers rooftop equipment supports, exterior strut and framing, parking structures, and damp mechanical rooms. For direct saltwater exposure or a chemically aggressive environment, stainless is the better call.

The thread is 1/4-20, 20 threads per inch, made to SAE J78-2013 with head dimensions to ASME B18.6.3-2010. Those are machine screw threads, so the screw will engage a standard 1/4-20 internal thread. Keep in mind it is a self-drilling screw, not a bolt, so its intended use is drilling and tapping its own hole in steel rather than being run into a pre-threaded nut.

A 5 inch Type BSD drill screw like the TXV145 earns its place when you can only reach one side of the connection. It drills, taps, and clamps in one pass, so you never need access behind the steel to hold a nut. If both faces are accessible and the connection is structural or will see repeated loading or vibration, a through-bolt with a nut and lock washer is the better detail. Where the TXV145 fits is heavy steel-to-steel fastening with blind backside access, and 150 lb-in minimum torsional strength is what lets it be driven that deep without snapping.

They ship in a jar with a 50 piece minimum, sold each. If your job needs a different length or a different count in the TXV series, Metallics makes other sizes and quantities available by request.