The Bromsgrove-based tooling expert Walter GB Ltd (www.walter-tools.com) has announced a range of two new solid-carbide taps and a thread-milling cutter targeted specifically at producing threads in hardened steel.

TC388 Supreme and TC389 Supreme solid-carbide taps are for materials with a hardness of 50–58 HRC and 55–65 HRC respectively; the TC685 Supreme thread mill is for workpieces up to 44 HRC.

The TC388 and TC389 Supreme taps have special cutting geometries that fully shear off the root of the chip when reversing, minimising torque peaks that are common with blind-hole tapping (reversing a tap can sometimes result in fractures).

In addition, the new geometries prolong the tool life and increase process reliability; and the need for oil lubrication has been eliminated by the use of emulsion.

Generating maximum process reliability and long tool life, the TC685 Supreme orbital drill thread mill produces the core hole and thread (and chamfer, if required) in a single operation.

Its face-milling geometry produces stabilising forces in the axial direction to improve stability and reduce deflection — resulting in fewer radius corrections and reduced wear. In addition, its 15deg helix angle and internal coolant optimise chip evacuation.