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

[Boyan Silyavski]

I've got both and the bevelled edge is far more versatile and the one used most.

You cannot angle the straight edge like you show because your straight reference edge is lost because it's bending and will just follow the curvature of the surface. The reference edge is only meant to be used in one direction and must be 90deg to surface your checking any tilt/bend and error is introduced.

Thanks, i get it now. Ok, i will look for a beveled one.

Now recapitulating everything it seems that the Maun even if not ultra accurate is made from carbon steel opposed to all other mentioned. And at theit web site i saw it was beveled.

So i send a couple of emails.

-To Maun, to ask them if its hardened carbon steel, cause at their web they don't say so, say steel. No carbon at any place. All sellers say carbon. We will see.
-To Measuresop which Greeny suggested, cause here they have some beveled straight edges which look quite cheap , so i asked about the accuracy.
-To Precison tools to see if they will ship to Spain this and if this can serve as a straight edge, cause it states tolerance 40micrometers
- to ebay member who is selling the Igaging 36 inch to ask if he could check straightness before sending. yes, back here, as the brand ones a very expensive.

Will see what happens.