Abstract
A great compressive residual stress is generated within the drilled surface layer, and hardness increases with the work- hardening in drilling of the high hardness material. If these functions can be positively given, the additional process such as shot-peening becomes unnecessary. Then, the conditions to give these functions by drilling was found from the change in the microstructure of drilling conditions and the drilled surface layer, and the relation among generated change in the microstructure and the residual stress, hardness, was found in this research.
