STAHLBERG bits come from a world-class manufacturer with many years of experience using the latest technology bits are made by precision forging - higher strength up to 20% compared to machined quality alloyed chrome vanadium grade steel used for production S2 - it is characterised by its toughness point hardness 61 - 62 HRC packed in a practical resealable case of 10 pcs size and type according to product name [***]