How straight is straight?

No, but that was never the issuse.

References to astronomy don't make you look good. For various reasons, I have learned to dismiss the astronomy types.

I can. YOu would have to live with my eyes for a day to appreciate that.

For a guy in his woodshop, no.

"CW" wrote in news: snipped-for-privacy@comcast.com:

Really? What types don't you dismiss?

Sure it does. Look up the CTE of a good stainless steel. Assuming a

2ft bar, the linear CTE is about 3x the tolerance for every degree F.

Now try the same with the elastic modulus. :-P

You want to pay extra money for a 5um tolerance, go for it. I'll save my money and buy something useful.

Most anyone but astronomers.

You're proving my point.