Metallics JTSF101 4 x 3/4 in. Flat Head Phillips Tapping Screws - Steel Zinc - Each

The JTSF101 is a Type A tapping screw with a gimlet point, so it starts itself in thin sheet metal, but it is not a self-drilling screw. It cuts its own thread in a pre-punched or drilled hole rather than drilling through solid stock. For a #4 screw, size the hole against the 0.172 inch gaging diameter so the threads have material to bite without splitting the metal.

Yes, if the hole is countersunk. The flat head on the JTSF101 measures 0.191 to 0.212 inch across and 0.055 to 0.067 inch high, so it seats below the surface in a matching countersink. On a flat, uncountersunk plate the head will stand proud by that head height. If you need it to sit on an unprepared surface, use a pan or round head instead.

No. The JTSF101 tapping screws are listed as not Buy American compliant and not ARRA compliant, with country of origin given as multiple. If your project carries a domestic sourcing requirement, these will not satisfy it.

A #1 Phillips bit. The JTSF101 is a Phillips drive screw with a #1 driver size, which is the right bit for the small #4 head. The recess measures 0.122 inch diameter and 0.081 inch deep, so a #2 bit will cam out and chew the recess.

Both the head dimensions and the threads follow ASME B18.6.4, with the dimensional spec cited as ASME B18.6.4-1998. That matters if you are matching a drawing callout or standardizing a fastener bin across a facility, because the head width, recess geometry and thread form will interchange with any other B18.6.4 #4 flat head Phillips Type A screw.

Carbon steel to AISI 1016-1024, case hardened to Rockwell C28-38, with a zinc finish. That hardness is what lets a Type A point cut thread in sheet metal without the tip rolling over. Zinc plating is a mild indoor corrosion coating, so for wet or exterior work pick a stainless or hot dip galvanized fastener instead.

They ship in a jar of 100, and 100 is the order minimum. Jar weight is listed at 0.2 lbs. If you need a different size or count in the same flat head Phillips Type A pattern, Metallics builds the JTSF series in other diameters and lengths.

That is what they are built for. Metallics lists the field application as the electrical, plumbing, heating and air conditioning trades, where a #4 x 3/4 in. Type A screw is the common fastener for attaching plates, straps and light sheet metal components.