303 stainless warping

[fishcat]

Started out surfacing 303 stainless plenty of cutting fluids ,little to no heat generated, simple shape just a radius around outer edge then a simple contour out the shape .After done machining part has large bow or warping, can anyone make a suggestion about what might be done to stop the warping Thanks

[Geof]

If you are cutting this out of plate or flat bar it is difficult to avoid warping. Stainless steel work hardens during the rolling process and there are a lot of stresses in the finished plate or bar. If you only machine on one side the stresses are relaxed unevenly and warping occurs. If you left the radius off you might find the warping is less.

Probably the only fix is to normalize or anneal the material before machining. This does alter the corrosion resistance a bit and may make it more difficult to machine. Annealed stainless is soft and behaves 'gummy' when being machined.

[Bill Ataras]

Thanks, Geof. This answers the question perfectly. Now I'm going to add to a growing pile of brass chips!

[txcncman]

Another way to handle this (still takes more time and money) is to start with about 0.125 oversize stock and rough machine it leaving about 0.010-0.015 per side for finish. Flip the part and repeat. Then flip the part for finish. Then repeat again.

[fishcat]

Thanks man, that is what I would normally do,just got caught up in the rush mode ,thanks agin