Chesterfield-based Dormer Pramet has launched an advanced barrel-shaped end mill for efficient five-axis machining for aerospace and die and mould applications. The new S791 cutter provides excellent surface quality and is suitable for semi-finishing and finishing in steel, stainless steel, cast iron and super-alloys.

It is the first design of its type within the company’s Dormer range and includes a nose radius for fillet milling, plus a larger tangential form for curved and deep wall surface machining.

Providing more overlap compared with conventional ball nose end mills, the barrel-shaped cutter achieves a greater area of contact with the workpiece, increasing tool life and lowering cycle time.

With fewer passes needed, it can help reduce machine time by half, while continuing to achieve all the usual benefits associated with a robust ball nose end mill.

In a recent example, the barrel end mill required just 18 passes, compared to 36 with a ball nose version, when machining with the same parameters.

The S791 achieves high surface quality, minimising the time spent polishing, and its positive rake angle enables smooth cutting action in stainless steels and super-alloys, reducing the risk of work-hardening.

An AlCrN coating provides thermal stability, reduced friction, excellent wear resistance and prolonged durability, with several three or four-flutes options available for more productivity (compared to a common two-flute ball nose cutters).