Sumitomo Electric Hardmetal CBN tooling developments

Sumitomo Electric Hardmetal is introducing a ‘hybrid’ series of CBN hard turning inserts, newly developed chipbreaker designs and, for holes as small as 2.5 mm diameter, an additional range of micro-boring bars.

Both the SumiBoron hybrids – the BNC2010 precision grade and more general purpose BNC2020 – feature multi-layered, heat- and wear-resistant micro-structured coatings on sintered CBN powder blanks having a substrate that incorporates a carbonitride binder.

To further improve performance, the company has also developed a series of ‘Break Master’ chipbreakers: N-FV and N-LV for finishing hardened steel; and N-SV for improved chip control when removing a carburised layer.

By extending CBN to micro-boring bars, the BSME and SEXC series are designed for holes as small as 2.5 mm diameter in hardened materials. In recent trials using SumiBoron BSME micro-boring bars on 60 HRc material, tool life was increased from 400 to 3,600 parts on CNC sliding-head mill-turn centres, says the company.