In the machine I manufacture we use a 5tpi ball screw. Currently we use a steel housing ballnut that rust in the environment that the machine is used in. Question being, is there a way to profile threads that have a radius crests to match the ball diameter size thats used in standard ball nuts? I want to cut a thread out of plastic (Acetal most likely) instead of using balls. Is this possible? A dumb idea? should we just get stainless housings with 440C balls which will rust anyway? Im all ears.