CBN Inserts

CBN (PCBN) Inserts

The polycrystalline cubic boron nitride (CBN) inserts offer a cost-effective alternative to the diamond tools. Although CBN’s exceptional toughness/hardness is still less than the diamond-based materials, it remains stable at temperatures of up to 1400°C, whereas diamond starts to decompose at 800°C. Additionally, its chemical resistance to ferrous materials is better than of PCD.

Common applications of CBN:
  • Alloy steels
  • Carbon tool steels
  • Die steel
  • High speed steel
  • Forged steel
  • Chilled cast iron
  • Inconel


    • CBN Inserts Working Materials And Cutting Speeds

    PROPERTY CARBIDE CERAMIC CBN PCD
    Hardness [HV] 1,300-1,800 2,100-2,400 4,500-5,000 5,000-6,000
    Price per Cutting Edge [USD] 4$ 10$ 40$ 160$
    Machining Hard Steel
    • 10 - 45 HRC
    • 50 - 100 mm/min
    • 160 - 320 SFM
    • 40 - 60 HRC
    • 100 - 300 mm/min
    • 330 - 660 SFM
    • 50 - 70 HRC
    • 150 - 350 mm/min
    • 500 - 1150 SFM
    		 N/A
    Machining Cast Iron
    • 200 - 300 mm/min
    • 650 - 1000 SFM
    • 400 - 800 mm/min
    • 1300 - 2600 SFM
    • 500 - 2000 mm/min
    • 1500 - 6500 SFM
    		 N/A
    Machining Super Alloys
    • 20 - 60 mm/min
    • 65 - 200 SFM
    • 150 - 400 mm/min
    • 500 - 1300 SFM
    • 100 - 400 mm/min
    • 330 - 1300 SFN
    		 N/A
    Machining Aluminum
    • 300 - 800 mm/min
    • 1150 - 2600 SFM
    		 N/A N/A
    • 600 - 2500 mm/min
    • 2000 - 8000 SFM

    Machining hardened steel with CBN inserts:

    Machining hard steel is the most popular application for CBN inserts because, for hardness above 50-55 HRC, it is the only practical solution besides grinding. Despite its high price, it is still the most economical solution for these applications.


    Advantages:
  • Excellent wear resistance.
  • Long tool-life
  • High cutting speeds
  • Maintaining close tolerances.
  • High surface finish[6]
  • Can replace grinding in many applications.
    • Disadvantages:
  • High price.
  • Low depth of cut. The depth of cut is limited by the size of the brazed CBN tips.
  • Solid CBN which enables heavier machining is far more expensive.

    • Machining Cast Iron with CBN inserts

    The more popular solution for fast metal removal on Cast Iron is with Ceramic inserts. Ceramic inserts cost less and can work in a higher depth of cuts. CBN inserts are used only for finishing operations that require higher surface finish and accuracy that cannot be obtained with Ceramic Inserts.


    Machining Super Alloys (Nickel Based) with CBN inserts

    The more popular solution for fast metal removal on Nickel Based Alloys is with Ceramic inserts. Ceramic inserts cost less and can work in a higher depth of cuts. CBN inserts are used only for finishing operations that require higher surface finish and accuracy that cannot be obtained with Ceramic Inserts.