North American Tool 422178 TR55x6.0mm 6-Flute TiN HSS Trapezoidal Hand Tap

The North American Tool 422178 is a new, USA-made TR 55×6.0 mm left-hand trapezoidal hand tap manufactured from high-speed steel (HSS) with a TiN (titanium nitride) gold coating visible across the full thread form, providing elevated surface hardness and lubricity for extended tool life. The double-lead (DB) trapezoidal thread form cuts a 55° included-angle profile at 6.0 mm pitch — a metric trapezoidal standard (DIN 103 equivalent) used extensively in lead screws, power-transmission screws, and actuator mechanisms where controlled axial load transfer is required. The 6-flute geometry, combined with the fluted brass HSG (hand-start ground) design and scalloped end face, provides chip division and smooth hand-tapping torque in through and blind holes; the square-drive shank accepts standard tap wrenches. Left-hand cutting direction and the "USA 422178" engraving on the shank are clearly confirmed in the photos, as is the North American Tool label on the original plastic case reading "TR55 X 6.0mm DB TRAPEZOIDAL HSG LH."

Product Specifications