Thanks Walter.

The part is gear for truck.
The spec is 0.35-0.55mm Arc and min 200% coverage
But the important is stress. it must be 800A at surface, 1200MPA at 0.02-0.05mm. This is quite dufficult to decide the process with media.
Have you meet this request before?
What kind of media would you recommend?

Thanks.

Dav