Hi,
I have 9/20 Lathe and matching size of Mill and turning and milling stainless quite often. I learned that using HSS to cut stainless -very low RPM and slow feed. Not very deep cuts naturally. HSS, High RPM and stainless steel just doesnt go, no matter what ever the feed is.
I burned so many HSS and stopping the work and re sharpening them wasnt much fun.
Now I am using carbide inserts, much better, comfortable feed and higher RPMs and nice surfaces.
Ah! I also discovered and using Olive Oil for cutting fluid.
I have tried all the others and none worked better. Yes! Plain Olive Oil. A drop of it to the tip of the carbide, at the beginning of the work, a drop at the middle and another drop for the finishing. (for medium size works) so, one liter goes for long ways (a year) at home shops. Especially for drilling stainless steel, it is ideal.
Instead of that acrid smell of stainless cutting fluid, you will have fried chips aroma around the shop as bonus.
It might be different for non-rubber stuff I dont know
Unal