Again many thanks for your information. The material I am refering to is 301 Stainless manufacture and conditioned in line with AMS 2431/4C.
After a little googling I found the 301 becomes magnetic when cold worked, but AMS 2431 doesn't call for any demagnetization.
With this being the case, we appear to have a magnetic field within our media, need to now check if this is in anyway transferred to the non-magnetic parts we are peening!
