Help In Buying A Good Straight Edge

[JSCOOK]

0.001 is 1/1000" therefore 0.0005" = 1/2000"

So I take it that .00050 is pretty accurate then. Anybody know what that .00050 would be in fractions?

[JSCOOK]

BTW, according to their website the 0.0005" is per inch length, not the levels entire length.

Empire True Blue

Assuming each inch in length was out the full 0.0005" over a 4ft length level: 48" X 0.0005" = 0.024" +/-

I was at Home Depot today and ran across the Empire " True Blue " level in 24", 48" and 72". They state that they are guaranteed to be within .00050 over the length of the level. Is that good enough for a straight edge? Cause if it is I just may buy one since I need a good level anyway and that would take care of two tools I need. Is even a true straight edge any better then that?

[lcm1947]

Thanks for correcting me JSCOOK. My mistake. That's what I get for trying to remember something without writing it down. That of course makes a huge difference but for the life of me can't figure out why they think that's a selling feature. Now if it were over the entire length then that would be impressive but per inch - who cares. Maybe I don't get their meaning?