I am trying to profile cut through 0.063 thick 300 series stainless. I cannot use a cutter any bigger than 0.25. Can anyone offer type of cutter with recommended speeds and feeds? Any help would be greatly appreciated.

Definitely a lefthand spiral righthand cut or downcut router (stub would be best). Depending on how you secure the part, and how many flutes you have, I'd say 6000 RPMish and .0015" fluteload. Coolant? What kind of machine are you using?

Beege,
I am using a Cincinnati five axis mill. (OLD) My max spindle rpm is 3000. I have tried 2 flute and four flute carbide and cobalt endmills. We are holding the formed part on a steel tube base with a with a fiberglass top vacuum fixture. We are using flood coolant. Is there any certain brand of cutter and or type you would recommend? Example carbide, hss etc? Thank you for your quick response.

Well, 3000 RPM, and 1/4" carbide is going to chip out. Carbide needs speed. So I'd go with cobalt HSS if you can find it. Onsrud is a popular maker.

1400 RPM, 3.6 IPM to start with. It's going to be slow.

303 stainless cuts easier than 304, which is easier than 316. 316 will work harden if you go too slow, and will be difficult to cut after that happens.

THANK YOU!! I will try this immediately.