The specialised operation to create bores between 6mm and 12mm in diameter in the 11% chromium, 1% manganese Martensitic stainless steel, follows the process development for a customer involving combinations of chip management through the cutting geometry of the gundrill coordinated with spindle speeds and feeds, coolant type and applied pressures.

Explains director of tooling Chris Barker: “This process development can now be applied across several industry sectors including medical, valve, aerospace and defence, hydraulic and automotive related areas where hole straightness and higher orders of surface finish is a growing requirement and especially in more difficult to machine materials.”