Metallics JTSF62 14 x 2 in. Flat Head Phillips Tapping Screws - Steel Zinc - Each

The Metallics JTSF62 is a Type A tapping screw with a gimlet point, so it forms its own thread in sheet metal and does not need a tapped hole. Size the clearance hole off the gaging diameter of 0.410 in. on the shank side and drill the receiving sheet undersized so the 10 threads per inch can bite. The gimlet point is made for thin sheet metal, not for heavy plate or masonry.

It will, provided the countersink matches the head. The flat head on the JTSF62 measures 0.427 to 0.462 in. across and 0.126 to 0.148 in. high, so an 82 degree countersink sized for a #14 flat head takes it flush with the surface. In a plain punched hole with no countersink the head stands proud by roughly an eighth of an inch.

Use a #3 Phillips bit. The recess is 0.276 in. in diameter and 0.160 in. deep, which is deeper than a #2 bit will seat in, and driving it with a #2 is how you cam out and strip the head. The screw is rated to 125 lb-in minimum torsional strength, so a properly seated #3 bit is what lets you use that.

They ship 100 to a jar, and 100 count is the order minimum. Total weight is 2.34 lbs for the jar.

Zinc plated carbon steel, built from AISI 1016 to 1024 material, is a dry interior finish. It handles indoor electrical and MRO work fine, but in exterior, wet, or corrosive locations the plating sacrifices and the steel underneath rusts. For those openings specify a stainless or hot dip galvanized tapping screw instead.

Both the dimensions and the thread form are to ASME B18.6.4, with the dimensional callout at ASME B18.6.4-1998. It is flagged Buy American compliant and ARRA compliant, with country of origin China. For federal or institutional submittals, that is the pairing the spec reviewer will want to see.

A Type A screw like the JTSF62 taps its own thread with a gimlet point but does not drill, so you need a pre-punched or pre-drilled hole. A self-drilling (Type TEK) screw cuts the hole and the thread in one pass. If the panel is already punched, as most electrical enclosures and strut channels are, the Type A is the straightforward pick; if you are fastening into blind unpunched metal, go self-drilling.

The JTSF62 is case hardened to Rockwell C28-38 and holds 125 lb-in minimum torsional strength, so it tolerates power driving. The failure mode to watch is over-torque after the gimlet point bottoms out in thick material, which shears the shank. Set the clutch rather than running the driver wide open.

The fastener length is 2 in., measured from the flat head bearing surface down to the gimlet point, since flat head screws are measured overall. Subtract your substrate thickness to see how much thread is left engaging the receiving sheet. For good holding you want at least a few full threads past the back face of the metal.