Metallics JTEKD29SS 12 x 1 in. 5/16 Indented Hex Head Self-Drilling & Tapping Screws with Washer - #3 Drill Point - 410 Stainless Steel - Each

The JTEKD29SS is 410 stainless steel, which is a hardenable martensitic stainless, hardened to Rockwell C38-46 so it can cut its own hole. It gives better corrosion resistance than plain plated carbon steel, which is why it gets specified on exterior strut, enclosures and rooftop work. It is not 300-series stainless, so in direct salt spray or chemical exposure it will not hold up like a 304 or 316 fastener.

Minimum torsional strength on the JTEKD29SS is 92 lb-in. Metallics notes that minimum torques are the same for stainless and steel self-drill screws, with drill time of 2.5 seconds through a 1 mm plate. Run them in a screw gun with a depth-sensitive nose or clutch; an uncontrolled impact driver will exceed 92 lb-in on a hard substrate and twist the head off.

Fastener length on the JTEKD29SS is 1 in. overall, and the screw is sized to drill and tap panel stock from 0.110 to 0.210 in. thick. Subtract the drill point and the thickness of what you are fastening through: with the point consuming part of that inch, 1 in. works for thin-gauge-through-panel stackups, not for deep standoffs or thick layered material.

A 5/16 in. hex driver or nutsetter. The head measures 0.305 to 0.312 in. across the flats, 0.34 in. across corners, with a head height of 0.139 to 0.155 in. It is a hex drive only, no slot to fall back on in a screw gun.

The washer is part of the screw, an indented hex washer head assembly. Washer OD runs 0.398 to 0.432 in. with a thickness of 0.022 to 0.039 in. That bearing surface spreads the clamp load so the head does not pull through thin sheet, and it means no loose hardware to handle on a lift.

It cuts a 12-14 UNC thread as it drives, 14 threads per inch, to SAE J78-2013. Because it taps a real UNC thread in the panel, a matching 12-24 machine screw will not thread into that hole; if you need to re-fasten, use another 12-14 self-drill screw or go up a size.

The JTEKD29SS is flagged both ARRA compliant and Buy American compliant in the manufacturer data, with country of origin listed as multiple. Dimensionally it is built to ASME B18.6.3-2010 with threads to SAE J78-2013, which are the standards a submittal package will ask for on a Type BSD self-drilling screw.

Type BSD means the screw drills its own hole and taps its own thread in one pass, so there is no pilot drilling step. That is what you want on steel panel, strut, enclosures and deck between 0.110 and 0.210 in. thick. A plain self-tapping sheet metal screw has no drill point and still needs a pre-drilled hole, so it is the choice when the hole already exists or when the material is too thick for this point to cut through.

They ship in a jar with a minimum order of 100 count. Metallics notes other sizes and quantities are available by request if you need a different length or diameter in the same JTEKD series.