Related Glossary Terms
- cubic boron nitride ( CBN)
cubic boron nitride ( CBN)
Crystal manufactured from boron nitride under high pressure and temperature. Used to cut hard-to-machine ferrous and nickel-base materials up to 70 HRC. Second hardest material after diamond. See superabrasive tools.
Workpiece is held in a chuck, mounted on a face plate or secured between centers and rotated while a cutting tool, normally a single-point tool, is fed into it along its periphery or across its end or face. Takes the form of straight turning (cutting along the periphery of the workpiece); taper turning (creating a taper); step turning (turning different-size diameters on the same work); chamfering (beveling an edge or shoulder); facing (cutting on an end); turning threads (usually external but can be internal); roughing (high-volume metal removal); and finishing (final light cuts). Performed on lathes, turning centers, chucking machines, automatic screw machines and similar machines.
Mitsubishi Materials has changed the stock status of coated cBN grade BC8020 from non-stock to stock standard. This includes 31 specific geometries that can handle severe turning applications in hardened steel. Inserts offered in GA style hone, BC8020 is designed for applications that are unstable or interrupted cutting. Coated cBN grade BC8020 is our first recommendation for more severe applications, where chipping may occur with current coated cBN grades. BC8020 exhibits excellent tool life in stable applications also, the company reports.