Tungaloy to Release a New Chipbreaker Solution for High-Feed Milling in Hardened Steel

October 2017, Iwaki – Tungaloy is adding its latest chipbreaker innovation to the DoFeed family. The new MH chipbreaker line is dedicated to machining ISO H workpiece materials.

DoFeed is a popular high-feed mill line designed for 3D-profiling and contouring ISO H materials, such as the die steels and pre-hardened tool steel blocks commonly used in the die and mold industry. The new MH chipbreaker is developed specifically for machining hardened steel of 50 HRc or above.

A common issue in milling hardened steel is unstable tool life due to unexpected chipping or fracture on the insert’s cutting edge. Incorporating a large wiper radius on its cutting edge, the MH chipbreaker enables a smooth tool entry to the hardened workpiece, reducing the risk of insert failures due to the abrupt impact at tool entry. The rake face angle is also optimized so as to enhance its robustness during tough hardened steel milling. Thus, premature insert failure due to chipping and fracture on the cutting edge is significantly reduced.

AH8015 and AH8005 are the standard insert grades of this line, featuring a high aluminum-content, multi-layered AlTiN coating with a dedicated carbide substrate for excellent resistance to fracture and wear. AH8015 is designed for hardened steel of 45–55 HRc, while AH8005 is ideal for hardened steel of 55 HRc and above.


  • At-a-glance:
    • High density milling cutter for ultimate efficiency
    • Chipping and fracture resistant, the MH chipbreaker perfect for machining hardened steel
    • AH8015 for hardened steel of 45 -55 HRc; AH8005 for 55 HRc and above


  • Total items to be added: 4 items