Hello Mr. Champaigne,
How are you?
I want to shot a tool steel for cold work (AISI M4). It's a punch for a sheet metal process. The problem is that the punch’s edge and the shear’s edge must be very sharp.
As you can imagine, after shot peening the edge it wasn’t sharp anymore so I have to grind the tool to sharpen again...
It's possible to improve these tools life using Shot Peening, without sharpness damage?
Have you ever seen this application before?


Steel AISI M4 60 – 62 HRc
Shot S 110 (57 a 64 HRc)
Air Pressure: 100 psi

Thanks in advance!
Ricardo Petersen

Perhaps fine particle shot peening might help. see this link:

http://www.shotpeener.com/library/pdf/2000007.pdf