Metallics TS57B 14 x 3/4 in. Pan Head Combo Sharp Point Tapping Screws - Steel Zinc - Each

A #3 Phillips bit drives the TS57B. The head is a combo recess, so a slotted blade works too (slot width 0.064 to 0.075 in., slot depth 0.06 to 0.085 in.) if you are hand-driving in tight spots. For powered installation stick with the #3 Phillips; the recess diameter is 0.274 in. and a #2 bit will cam out and chew the recess.

The TS57B is a Type A tapping screw with a gimlet (sharp) point, so it pierces and forms its own thread in thin sheet metal without a separate tapping operation. In light gauge steel or sheet metal enclosures it drives straight in. In heavier gauge or structural steel you still want a pilot hole, since the sharp point is made for thin stock, not thick plate.

The TS57B measures 3/4 in. under the head at a #14 diameter with 10 threads per inch, so you get roughly ten thread turns of total engagement. Practically that means your combined material stack plus the thickness of whatever you are fastening needs to stay under 3/4 in., and you want at least two or three threads past the back face to hold. For deeper stacks order a longer length in the same JTS series.

Carbon steel at AISI 1016 to 1024, case hardened to Rockwell C28 to 38, with a minimum torsional strength of 125 lb-in. That is the figure to watch if you are driving with an impact driver, since it is easy to exceed on a #14 screw once the head seats. Back the clutch off and let it stop on contact.

The TS57B is steel with a zinc plated finish, which is a coating meant for dry indoor service: panel boards, enclosures, strut accessories, interior sheet metal. In exterior, wet, or coastal work the plating will eventually rust through and stain the substrate, so specify stainless for those openings instead.

These ship as a 3,000 piece box, which is the order minimum on the TS57B. The full box weighs 32.53 lbs. If your job only calls for a handful, this is a stocking quantity rather than a job-count purchase, so it suits an MRO crib or a contractor who uses #14 pan head tappers regularly.

The TS57B is flagged as both Buy American compliant and ARRA compliant in the manufacturer's data, which is what procurement on federally funded work normally asks for. Country of origin is listed as multiple, so if your specification requires a single named origin on the submittal, that is the detail to pin down before release.

Type A with a gimlet point, like the TS57B, is for thin sheet metal, sheet metal boxes, and light gauge work where the point can pierce and form its own thread. A self-drilling screw with a drill point is what you want when you are going into heavier gauge steel or structural members and need the screw to cut its own hole. Pick by substrate thickness: thin sheet, Type A; thicker steel, self-drilling.

Dimensions follow ASME B18.6.3-2013 and the thread form follows ASME B18.6.4, the tapping screw thread standard. Material is AISI 1016 to 1024 steel. Note that on the #9 diameter in this family the dimensions are independent of ASME B18.6.4; that caveat does not apply to the #14 TS57B.