I just received some sample parts from my machinist and would like some input before I speak with them regarding this issue.
Some of the sample parts have a hazy, almost matte surface finish on a particular horizontal surface. I'm assuming this surface is machined with an end mill as opposed to a face mill simply due to the small size of the part and the adjacent vertical surface that lends itself to machining via end mill.
I would like to know possible causes for this to educate myself. Any responses are appreciated.