Princes Risborough-based Sumitomo Electric Hardmetal Ltd (www.sumitool.com) has developed the GS chip-breaker to improve process control when milling shoulders and slots involving depths of cut up to 6mm in steel and cast-iron workpieces.

The GS complements the existing XNMU series of chip-breaker inserts for Sumitomo’s SEC-Sumi Dual Mill (DFC) cutter (pictured).

XNMU inserts are designed to reduce tooling costs, as they are available in double-sided variants with six corners.

The cutting edge of the GS chip-breaker is set at 25deg, with a range of corner radii between 0.16 and 0.63mm.

This design, which also incorporates a wiper edge, is said to enhance toughness.

DFC cutters include shank bodies with diameters between 25 and 80mm and with standard and fine pitches (with between two and seven teeth).

Shell mills are available in diameters between 50 and 160mm in standard, fine and extra-fine pitch variants (with between four and 16 teeth).