Dormer Pramet has launched a new series of chip breakers for turning and bar peeling.

Dormer Pramet – a merger of rotary tooling manufacturer Dormer and indexable specialist Pramet creates a single platform, providing customers with access to a wide range of high quality, fit-for-purpose products including hole-making, milling, turning and threading tools.

The negative NRM turning chip breaker is for roughing and semi-roughing of stainless steel and low alloy steel. Launched under the company’s Pramet brand, NRM is available for both double-sided and large single-sided inserts. It has been designed for continuous and mass levels of production, offering consistent performance and high feeds. However, the NRM has excellent chip-breaking properties and can also be used for roughing of stainless steel even at lower feeds, without the risk of work hardening.

Its positive geometry with a wide T-land offers a broad depth of cut and promotes good chip evacuation in a wide number of applications. The chip breaker is available in grades T7325, T7335 and T9315. The NRM enhances Pramet’s existing range of turning chip breakers for stainless steel, including the NMR for medium to roughing operations, NM for medium turning and NF for finishing to medium turning.

In a recent test, machining M group material DIN 1.4301, the NRM on the CNMG insert with T7335 grade, achieved a 60 per cent longer tool life than a competitor equivalent.

Apart from this, Dormer Pramet has developed a new chip breaker for bar peeling of stainless steel, steel and super alloys. Suitable for roughing to finishing operations, the MM chip breaker has been designed with a wide, strong T-land to offer increased stability of the cutting edge. This gives the Pramet chip breaker good chip control with an even spread of the cutting forces, making it suitable for high feeds in heavy conditions.

There are three cutting edge options: S01 is for hard materials, S02 for medium hardness and S03 have a stabilised facet on the main cutting edge for soft materials. The MM chip breaker is available for use with the LNGF inserts, for roughing to finishing, RNGH inserts for roughing and WNGF inserts for roughing to finishing. It is suitable for use with the grades T7325, T9315 and T6310.