Sumitomo Electric Industries, Ltd. (head office: Chuo-ku, Osaka, President: Osamu Inoue, hereafter "our company") has developed AC4115K, a coated grade optimized for the continuous machining of cast iron, and will be launch for sale from May 2026. By applying our proprietary CVD coating technology - Absotech™, wear resistance is significantly improved, contributing to longer tool life and reduced machining costs.

Cast iron is widely used in various industries, including the automotive sector, where gray cast iron*1 is used for engine blocks and brake discs where sliding properties are required, while ductile cast iron*2 is used for differential cases and carrier cases where strength is required.

In recent years, in order to improve fuel efficiency through reducing the vehicle weight, there has been a trend to make parts thinner and stronger, and proportion of using high-strength ductile cast iron (FCD600 and above), which has strength close to that of steel, is increasing. With this increase in work material strength, cutting tools are required to have even greater wear resistance than before.

In response to these needs, our company has developed AC4115K, which is optimized for continuous machining of ductile cast iron. It provides excellent wear resistance, contributing to longer tool life and significantly reducing machining costs.

Our company will continue to provide highly efficient machining solutions that contribute to improved customer productivity and cost reduction.

Coated Carbide Grade for Cast Iron Turning AC4115K

1. Features

(1) Application of proprietary coating technology
Our 1st recommended grade for continuous machining of cast iron in our company's product lineup. Through the use of Absotech™, our proprietary CVD*3 coating technology, to combine an alumina layer with further-refined crystal orientation control technology with a carbide substrate that has excellent resistance to plastic deformation, wear resistance is significantly improved. This enables longer tool life in continuous machining of cast iron.

(2) Adopts a gold exterior
The use of a gold-colored exterior makes it easy to identify used corners, contributing to more efficient tool management on site.

(3) New chipbreaker lineup
New additions to the AC4115K lineup include, a SU type chipbreaker in negative insert for finishing, a SU type chipbreaker in positive insert for light to medium cutting, and a LUW type chipbreaker in positive insert for finishing to light cutting.

  • SU type chipbreaker (Negative): For finishing. Effective for small depths of cut and high feedrates.
  • SU type chipbreaker (Positive): For light to medium cutting. A general-purpose chipbreaker with excellent sharpness.
  • LUW type chipbreaker (Positive): For finishing to light cutting. A high-performance chipbreaker for finishing with a wiper edge.

2. Lineup

Insert: Total of 292 Cat. Nos.


*1 Gray cast iron:
A type of cast iron primarily composed of carbon (C) and silicon (Si), with a high percentage of carbon in the form of graphite, resulting in a grayish fracture surface appearance. It has excellent sliding properties.

*2 Ductile cast iron:
A type of cast iron. By adding magnesium and cerium, the graphite structure becomes spherical, giving it higher strength than gray cast iron.

*3 CVD (Chemical Vapor Deposition):
One of the coating deposition methods, which uses raw material gas to form a thin coating film through chemical reaction on the surface of a substrate material.