Metallics TS27B 10 x 1 in. Pan Head Phillips Sharp Point Tapping Screws - Steel Zinc - Each

The TS27B is a Type A tapping screw with a gimlet (sharp) point, which is the type meant for thin sheet metal, and the point lets it start its own hole in light gauge material. In heavier sheet or in any material that resists, drill a pilot: the thread is a coarse 12 threads per inch, so it needs clearance for the shank, not the threads. It is not a self-drilling screw, so there is no drill flute to cut heavy steel.

Both the Buy American and ARRA compliance flags on the TS27B read as compliant, which is what a government, school district, or federally funded institutional buyer needs on the submittal. Country of origin is listed as multiple, so the sourcing varies by production run.

Dimensions follow ASME B18.6.3-2013 for the head and recess, and the thread follows ASME B18.6.4, the tapping screw thread standard. Steel is AISI 1016 to 1024, case hardened to Rockwell C28 to 38, with a minimum torsional strength of 48 lb-in. That combination is what a spec writer is checking when the drawing calls out a standard tapping screw rather than a proprietary fastener.

The TS27B ships as a box with a 4,000 piece minimum, so this is a bulk buy for shops running sheet metal, panel, or box work continuously rather than a handful for one repair. The boxed quantity weighs 22.84 lbs. Other sizes and quantities are available by request if 4,000 of this size is more than you need.

A #2 Phillips bit. The recess is 0.186 to 0.199 inch in diameter and 0.124 inch deep, which is standard #2 Phillips territory, so a worn or undersized bit will cam out before the screw seats. Keep a fresh #2 in the driver if you're running these in volume.

Usable grip is driven by the 1 inch length: subtract whatever the point and lead thread consume and you have the engagement. For sheet metal work that means fastening a top layer up to roughly half an inch while leaving thread in the receiving sheet. The pan head adds 0.122 to 0.133 inch above the surface and spans 0.357 to 0.373 inch, so it bears on the material rather than pulling through a punched hole.

They stand proud. A pan head is not a countersinking head, so expect 0.122 to 0.133 inch of head above the material with a 0.357 to 0.373 inch bearing face. If you need the fastener flush in the sheet, you want a flat head with a countersunk hole instead, not this pan head.

Zinc plating over carbon steel is a mild corrosion coating meant for dry or sheltered interior use, which covers most electrical panel, enclosure, and duct work. For sustained exterior exposure, washdown areas, or coastal air, zinc plating will eventually bloom and rust; a stainless or hot dip galvanized fastener is the right call there. The TS27B is steel with a zinc finish.

A Type A screw like the TS27B has a gimlet point and coarse 12 TPI thread: it forms its own thread in thin sheet metal but relies on a punched or drilled hole in anything substantial. A self-drilling screw carries a drill point with flutes and cuts its own hole in heavier gauge steel in one pass. If your substrate is light gauge sheet or already has holes, the Type A is the cheaper and faster fastener. If you are going into structural steel or thick plate with no pre-drilling, you need the self-drilling type.

Torsional strength is rated at 48 lb-in minimum, with case hardness at Rockwell C28 to 38. That is the figure that matters if you are driving with an impact or a high torque screw gun: back the clutch off below that and heads stay on. Snapped tapping screws almost always come from over-torquing past the rated value rather than from the material.

Model and MPN are both TS27B, in the Metallics JTSP series of pan head Phillips sharp point tapping screws. Reference it as TS27B when reordering or cross-referencing to another size in the same family.