Metallics TS2110M 8 x 1 in. Pan Head Phillips Sharp Point Tapping Screws - Steel Zinc - Each

The Metallics TS2110M is a Type A tapping screw, meaning it has a widely spaced thread (15 threads per inch) and a gimlet (sharp) point that drills and forms its own thread as it goes. That combination is meant for thin sheet metal and resinous plywood type work, not for thick steel. For heavier gauge metal you want a finer thread Type B or a self-drilling point instead.

They go out in box quantities of 10,000 pieces, which is the order minimum. If you need a smaller count or a different length in the same #8 pan head Phillips sharp point pattern, Metallics lists other sizes and quantities as available by request.

The TS2110M is flagged compliant for both Buy American and ARRA. Country of origin is listed as multiple, so if your specification requires documentation of a single source, ask for the certification on the specific lot you are buying.

Use a #2 Phillips bit. The recess is 0.169 to 0.182 inch in diameter, 0.108 inch deep, with a 0.03 inch slot width, which is standard #2 Phillips geometry. Driving it with a #1 will cam out and a #3 will not seat.

The pan head on the TS2110M measures 0.306 to 0.322 inch across and 0.105 to 0.115 inch high, so it sits roughly an eighth of an inch proud of the work. A pan head is not countersinking, so if you need a flush surface, specify a flat head instead.

Head dimensions follow ASME B18.6.3-2013 and the thread follows ASME B18.6.4. Steel is AISI 1016 to 1024, case hardened to Rockwell C28 to 38, with a minimum torsional strength of 39 lb-in. That hardness and torque figure is what keeps the screw from snapping when it taps its own thread. Note that Metallics states dimensions for the #9 diameter are independent of ASME B18.6.4.

The TS2110M is steel with a zinc finish, which is a plating for dry indoor and protected service, typical for electrical rough-in, box mounting, and sheet metal work. For exterior exposure, wet locations, or contact with treated lumber, specify stainless or hot dip galvanized instead; zinc plate will corrode there.

The TS2110M has a 1 inch overall length under the pan head. A Type A screw needs enough thread engaged past the back of the material to form a thread and hold, so with a 1 inch screw you have room for the fastened member plus engagement; if you are stacking more than about three quarters of an inch of material, step up to a longer length. Metallics lists other lengths in the same pattern by request.

A full box runs 51.11 lbs and measures 9 x 9 x 6.13 inches. Worth knowing before you load a van or plan a single-person carry up a ladder run.