Cutting Inserts for Hard Material Machining

Material Options

1. CBN (Cubic Boron Nitride) – First choice for materials over HRC50

   Hardness second only to diamond; no chemical reaction with ferrous metals (diamond cannot machine steel).

   Retains hardness at 800～1300°C.

   Disadvantages: Low toughness, poor impact resistance. Not for heavy stock removal or interrupted cutting. Not applicable for aluminum and titanium alloys.

   Application: Semi-finishing & finishing of hardened die steel, bearing steel, chilled cast iron.
2. Ceramic Inserts (Alumina / Silicon Nitride Ceramic)

   Excellent hot hardness, low friction coefficient, lower cost than CBN inserts.

   For hardened steel & cast iron HRC42–60.

   Lower toughness than CBN. Shock and interrupted cutting are prohibited; only for stable continuous cutting.
3. Coated Cemented Carbide Inserts (For hardened steel ≤ HRC48)

   Substrate: Ultra-fine grain carbide for improved toughness.

   Coating: TiAlN, AlTiN, silicon-based nano multi-layer composite coating.

   Good high-temperature oxidation resistance. Only works for medium-hard materials, inferior to CBN/ceramic for ultra-hard workpieces.

Quick Selection Guide