CBN Turning Inserts | Lathe Tool Supplier | Cutwel Ltd
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CBN Turning Inserts

Cubic Boron Nitride Turning Inserts for Hardened Steel Turning

Turning hardened steel (45-70 Rockwell) with a sintered carbide insert is not normally possible and will result in rapid tool failure and, depending on the metal hardness, not even cut the metal. Typically, most people will send hardened or heat treated turning parts away for grinding which can be a slow and expensive process. 

Cubic boron nitride (CBN) offers a cost alternative to grinding with stable and long tool life.  A piece of CBN is brazed onto a solid carbide blank to create a CBN turning insert. CBN Inserts are available in 4 forms:

  • Regrindable (single edge)
  • Non-regrindable (multi edge)
  • Non-regrindable coated (multi edge)
  • No-regrindable (single edge)


CBN turning inserts from Korloy will fit into your existing turning tool holder or boring bar. Simply match up the first 2 letters of the insert code (e.g. CNMG carbide insert = CNGA CBN turning inserts). Due to the hardness of CBN inserts, they are very brittle and vibration can cause them to chip easily.  To prevent tool failure we recommend always to use double clamp turning tools or boring bars such as a DCLNR, DDJNR or DTGNR which can help eliminate tool failure caused by vibration.  Buy online today.