Why stainless steel products are magnetic?

Austenite stainless steel such as SUS304 are not magnetic in the state of fluidization, but magnetism might occur by cold forming.  This is because austenitic organizations transforms into martensite.
So when we proceed plastic working such as lengthning, rolling and molding retaining rings, it will be feeble magnetism.
If you want nonmagnetic products, we recommend you to demagnetize or hire SUS316 which is hard to transform into martensite.