Dry continuous turning of a gray cast iron (GCI)

For an OEM customer looking to machine gray cast iron (GG250) with CNMG 120408 inserts, we are looking for the best coating. The dry continuous turning process has a cutting speed of 400 m per minute, a feed of 0.35 mm per revolution and an axial depth of 2.0 mm. The main issue with gray cast iron is its low impact strength, leading to brittle behavior and abrasive wear. In most other respects, machinability is very good.

Problems encountered:

Recommendation is a coating with:

  • Only abrasive wear
  • High hardness


  • High thickness

Our recommondation

Ionbond CVD 29 HSA Plus Black is exceptionally well-suited for high-volume machining of cast iron and cast steel at medium to high cutting speeds and high temperatures due to the thermo-dynamically stable structure of its ceramic content.

Ionbond™ CVD 29 HSA Plus Black