Thanks for Bill Barker's advice and I know many shot peening manufactures buy peening machinces from PTI. PTI shot peening machince is well-known to peen blade or engine parts in China and the specification of shot peening of aeronautical industry was made by me. I want to know the limited size of diameter of small holes which can be peened.
Dr. Yu-kui GAO,
Surface Enhancement Modification Group Leader,
Beijing Institute of Aeronautical Materials,
P.O.Box 81-5, Beijing 100095, China