Mitsubishi softens the issue of hard machining

Nickel based heat resistant alloys such as Inconel 718 are regarded as formidable opponents for the cutting tool industry. However, the composition of these materials sees them soften when heated to temperatures beyond 800 degrees C, making them easier to machine. To efficiently carve through these difficult to cut materials, Mitsubishi Materials has now developed its innovative new line of ceramic end mills, the CESRB Series.

Whereas cemented carbide end mills deteriorate drastically when working beyond 800 degrees C, the new range of ceramic end mills retains their strength. This enables them to conduct high speed machining with large depths of cut and at high feed rates on difficult to cut materials such as Inconel. Capable of working at parameters beyond that of carbide end mills, ceramic end mills can double tool life whilst machining at feeds and speeds up to 10 times higher than conventional tools.


Ceramic end mills – Extreme heat generation for high metal removal rates


The concept behind this new range is that it should run without coolant at high speeds and feeds with relatively heavy depths of cut to generate higher frictional heat. By generating an increase in temperature, the component material softens and enables the end mill to work more efficiently. As such, the Mitsubishi R&D department suggests that these new end mills operate at speeds from 13000 to 26000rpm depending upon tool diameter, with feed rates in the region of 1.5 to 2m/min.

Ideal for Inconel applications in the aerospace and power generation sectors, the performance of the new CESRB range is credit to its ceramic composition and the innovative geometry. The creative geometry design incorporates an optimised helix angle that reduces cutting forces and prevents the ‘pull-out’ effect that is common during heavy machining.

Furthermore, Mitsubishi has utilised its seamless grinding technology to deliver a higher edge chipping resistance, even during extreme roughing applications. These features are supported by a strong negative flute and specially developed rake edge that withstands high temperatures and loads.




Further enhancing the performance characteristics is the fact that they are available with a four-flute designation for pocketing and slotting operations, whilst a six-flute design is available for face and profile machining. The four and six fluted end mills are available in diameters of 6, 8, 10 and 12mm with a corner radius of 0.5, 1 and 1.5mm depending upon the chosen diameter. The respective diameters are provided with a 6, 8, 10 and 12mm shank. To maximise rigidity and performance, the ceramic CESRB series has a stub length design with an overall length of 50, 60, 65 and 70mm and a cut length of 4.5, 6, 7.5 and 9mm for the selected diameters.

Due to the high performance characteristics of this new ceramic range, Mitsubishi recommends that customers utilise a robust machine tool with a sturdy tool clamping configuration such as a precision hydraulic chuck.

For further details contact Multitrade Distributors on TEL: 087 803 2377 or visit