> how many machine shops are willing to spend $2-5K on a
> surface roughness gage?
Yep, I wouldn't spend it on that tool. But I'd wanna be prepared for the geek like me that brings in his parts and states the finish he wants on them.
As I see it, shops know their tools and know what finishes they produce. I'm not sure I wanna work with a shop that doesn't, so I gotta ask. And if I gotta ask, I gotta know.
I'm really after an understanding what it's about and what it is supposed to be. At this point I speculate that the finish is specified by manufacturer of the contact materials, i.e. the gasket, ring or bearing manufacturers.