18 January 2024

Sumitomo Electric Industries, Ltd. (head office: Chuo-ku, Osaka, President: Osamu Inoue, hereafter "our company") has developed and launched the tool grade AC4125K, for interrupted machining of cast iron, for sale as of December 28, 2023.

Cast iron is used in the automotive industry among many other fields, where gray cast iron*1 is used for parts such as engine blocks and brake discs where sliding is required, while ductile cast iron*2 is used for parts such as differential cases and carrier cases where strength is required.

In recent years, the ratio of high-strength ductile cast iron (FCD600 and above), with high strength and poor machinability, has been increasing, in order to reduce thickness and weight in consideration of the global environment. In addition, parts machining is increasingly subjected to harsh cutting environments such as interrupted machining of complex shapes and rough machining where cast surface is machined as it is, leading to tool life fluctuation due to cutting edge chipping becoming an issue.

In response to these issues, our company has developed the coated grade for cast iron turning AC4125K. Although priced the same as our company's conventional tools, it helps reduce machining costs by lowering tool usage and tool change frequency through stable and longer tool life.







1. Features
Our 1st recommended grade for interrupted machining of cast iron. Through the use of AbsotechTM, our proprietary CVD*3 coating technology, to provide excellent chipping resistance by maximizing compressive stress to realize stable and longer tool life for roughing of components such as differential cases and carrier cases. In addition, the use of a gold exterior makes it easy to identify used corners, contributing to easier tool management.

2. Lineup
Insert: Total of 244 Cat. Nos.
(December 28, 2023: 128 Cat. Nos. for sale; February 2024: 116 Cat. Nos. for sale)

3. Sales Plan
90 million JPY in the first year, 340 million JPY/year after 3 years

4. Price
Priced the same as our company's conventional tools
(Standard Product) CNMG120408N-GZ: 980 JPY (excluding tax)

*1Gray cast iron:
Cast iron is an alloy primarily composed of carbon (C) and silicon (Si), with C content of 2.1% or more. Gray cast iron is a type of cast iron that appears gray on the fracture surface because carbon is more present in the form of graphite than in the form of cementite.

*2Ductile cast iron:
A type of cast iron containing somewhat more carbon and silicon than gray iron, with the graphite becoming spherical due to the addition of magnesium and/or cerium.

*3CVD (chemical vapour deposition):
One of the coating deposition methods, which uses gas reaction to form a thin coating film. Raw material gas containing the ingredients of the target coating is supplied to a heated substrate material in a reaction chamber, forming the coating through chemical reaction in the gas phase or on the substrate surface.