In general, for machining materials such as pearlitic grey cast iron, powdered metals, high temperature alloys and hardened ferrous metals (>45 HRc) where sever interrupted cuts are involved, the higher percentage CBN grade is used.

The higher, percentage ceramic-based CBN can be used for rough and finish machining of hardened ferrous metals (>45 HRc) operations where hard turning is replacing grinding and for continuous as well as interrupted cuts in finish machining.

While using CBN tools, the following guidelines are recommended:

• Use rigid machines with sufficient horsepower
• Keep minimum tool overhang
• Use negative rake tools and largest lead angles whenever possible.
• Although use of coolant is not mandatory, cutting fluid is generally recommended on long-cut operations.
• A proper chamfer should be ground on the cutting edge to minimise edge chipping and increase edge strength. Larger angles and width may be required for severely interrupted cuts. Radius honing is also recommended for severely interrupted cuts