Chipbreakers for PCD tools have been around for almost 10 years, with German diamond toolmaker, Lach Diamant having been a pioneer in this field. Lach's first patent application for PCD chipbreakers was granted in January 1999, a development that was aimed particularly at the use of PCD tooling in the aerospace and automobile industries.


In both these industries in recent years there has been a move towards the use of lightweight aluminium alloys for weight saving and therefore reduced power requirements. Certain high strength forging alloys in particular pose severe problems during the machining process because of the tendency to generate unwanted ribbon-type chips and thread chips. These not only inhibit the performance of the cutting tool but can also cause damage to the machines, which involves unwanted shutdowns to remove clogged up areas.
As can be seen in the photos on the left, the use of chipbreakers eliminates this problem and allows for efficient and trouble-free production.

Lach has now taken this a step further by introducing a new PCBN cutting insert program under the brand name of CBN-DUO-power, which includes a chipbreaker. This development was shown for the first time at this year's AMB exhibition in Stuttgart, Germany.
These CBN chipbreaker inserts from the dreborid program are recommended by Lach for the cutting of grey cast iron using positive geometry as well as for the finish machining of hardened steels - in both cases the innovative chipbreaking design prevents the generation of undesirable ribbon and thread chips.