Help needed with understanding accuracy in measuring tools. I want to go straight :-)

[mekanik]

Hi M8
This is only my opinion and i am sure others may disagree but i would forget about the Maun straight edge, i couldn't see any thickness quoted so it's more than likely a bendy one,the other bevel edge rule is quoted as steel and galvanised and i didn't see any tolerance/flatness quoted, i would stick with the magic numbers DIN 874/2 a parallel straight edge of reasonable thickness should be fine you can see the smallest of gap by placing a light behind the straight edge.
Take no notice of e-bay sellers the DIN 874/2 rules will be checked under controlled temperature conditions in a tool room using some rather expensive gear. a box for your precision straight edge is a must buy.
Hope that helps, i am now awaiting the flack.
Mike