Magnetic Permeability of 303 Stainless Steel 2

[nca]

Is it possible for the magnetic permeability of 303 stainless steel to rise after it is machined, allowing you to feel resistance when you pass a magnet over the material?

 

[Aquila]

we have found the same problem.  Does 303 stainless rod become magnetic after machining. If so, what is the allowable magnetism.

 

[hank]

Type 303 and other 300 series austentic stainless steels will be magnetic after cold work. The equilibrium crystallographic phase for these materials is austenite or face centered cubic, which is not ferromagnetic. Plastic deformation will cause a deformation induced phase change to martensite, which is body centered tetragonal and ferromagnetic. <br><br>Machining can cause sufficient deformation at the surface to cause noticeable magnetic permeability. This condition can probably be corrected by taking lighter final machining cuts.