1.high-performance high speed steel., 2. e.g. M2, M2AL, M35, M42, ASP2030 etc, 3. multi-cut ... system.3. Applicable to hole cutting and process of annular groove on various magnetic drills and press, like Alfra, Hougen, Jancy ... , BDS, Ruko.4. Made of high-performance high speed steel., e.g. M2, M2AL, M35, M42 etc. And can be used ...