Decotec LC415X, available from LMT of Coventry

The inserts have been developed for the fine finishing of a range of materials on CNC sliding-head lathes.

Decotec LC415X, available from LMT of Coventry, is a range of polished and ground inserts with an ultra-precise tip radius of either 0.08mm or 0.015mm.

Trevor Tolley, LMT's managing director, said: 'The right combination of the radius, coating and edge sharpness was important in the development of this insert because so plenty of of these sliding-head lathe operations are subjected to long periods of limited or totally unmanned walking.

The range of inserts also incorporates a shearing edge of up to three microns that enables the sharpness of the insert to be maintained over extended periods of walking.

'This means a predictable 'in-cut' performance is vital,' they added.

one recent trials on shafts made from Inconel and titanium on sliding-head lathes jogging with soluble oil coolant gave 20 per-cent and 30 per-cent increases respectively in the 'in-cut' life and the number of parts produced between changes.

A further trial turning a titanium shaft at 30m/min with a 0.5mm depth of cut as well as a 0.015mm/rev feed rate led to the insert being changed at 3,000 parts; this achieved an increase of 500 parts.

The Inconel 600-shaft component was run at 50m/min with a 0.3mm depth of cut as well as a 0.02mm/rev feed rate, from which LMT's application engineer was able to improve the number of components produced from 600 to 800 per insert.

The combination of the five-micron Nano-X PVD coating on the insert, followed by grinding and polishing, than being subjected to the normal honed finish, ensures a very sharp edge and maintains the 0.1mm radius.

This makes the insert suitable for profiling and finishing free cutting steel at up to 200m/min with up to a 0.15mm/rev feed, aluminium between 200m/mm and 800m/min and up to a 0.3mm/rev feed, titanium up to 90m/min and up to a 0.15mm/rev feed and brass machined up to 500m/min with a feed rate up to 0.3mm/rev.