Metallics TXV146D 1/4-28 x 6 in. 5/16 Hex Head Heavy Duty Drill Screws - #5 Drill Point - All-Weather - Each

The TXV146D carries a #5 drill point, the heaviest point class Metallics puts on its Type BSD heavy duty drill screws, intended for steel-to-steel work. The screw is 6 inches long with 1/4-28 threads, so the point drills the hole and the threads tap it in one pass. The limiting factor is the point size, not the length: a #5 point is the one you pick for structural-gauge and plate steel rather than light sheet. For light-gauge decking or studs, a smaller point screw is the cheaper and faster choice.

Torsional strength is rated at 150 lb-in minimum and the screw is case hardened to Rockwell C32-40, which is what lets the point drill hardened steel without the shank twisting off. Dimensions follow ASME B18.6.3-2010 and the thread follows SAE J78-2013, so it meets the published standards for tapping screws rather than being a proprietary profile. Keep the gun at full speed and steady pressure; backing off mid-hole is what usually kills a drill point.

Country of origin is the United States, and that is called out in the product features as well. However, the item is not flagged Buy American compliant and is not ARRA compliant, so it should not be submitted as a compliant line on a federally funded project that carries those clauses. For a domestic-preference job, have the specifying authority confirm the requirement before you substitute it in.

A 5/16 inch hex socket or nutsetter. The head is a hex head with hex drive, measuring 0.367 to 0.375 inch across the flats and 0.409 inch across the corners, with a head height of 0.172 to 0.19 inch. Drive it with a screw gun or impact driver fitted with a magnetic 5/16 nutsetter; there is no cross or square recess on this head.

It is finished with zinc plus an all-weather coating, which is what Metallics specifies for exposed and damp locations rather than a plain zinc screw. That makes it suitable for rooftop, exterior strut, and unconditioned-space steel-to-steel fastening. It is a coated carbon steel screw, not stainless, so it is not a choice for continuous saltwater immersion or highly corrosive chemical environments.

A washer is integral to the screw: the washer OD runs 0.480 to 0.520 inch with a thickness of 0.030 to 0.050 inch, under the 5/16 hex head. Nothing separate needs to be ordered for the washer itself. Note it is a metal bonded washer dimension only, so if your detail calls for an EPDM-sealed penetration, verify your spec against the roofing or enclosure requirement.

25 each is the order minimum, supplied in a jar. The 1/4-28 x 6 inch size is a specialty length, so it is sold in that jar quantity rather than loose singles. Metallics does make other sizes and quantities in the TXV series available by request if 6 inches is longer or shorter than your assembly needs.

Type BSD is the heavy duty class in the self-drilling family. On the TXV146D that means a #5 point, a 1/4-28 fine thread, and a hardened carbon steel body rated to 150 lb-in torsion, meant for joining steel to steel. A standard light self-drilling screw (a #2 or #3 point with coarser thread) is built to pierce thin sheet or attach to light framing, and it will fail or burn up in heavy plate. Pick BSD when both pieces are structural-weight steel; pick the lighter screw for sheet metal, duct, or track.