The levelness tolerance indicates the max deviation between the lowest and highest point (temperature of + 20°C).
Levelness tolerance (flatness) in ?m for different degrees of precision.

Engineer?s rulesStraight-edges
Length in mm
? 2
00012Length in mm
? 2
00
500 4 7 12 21 75 2
750 6 9,5 17 27 100 2
1000 8 12 21 33 150 3
1500 - 17 29 46 300 3
2000 - 22 37 58    
2500 - 27 46 71    
3000 - 32 54 83    
4000 - 42 71 108    
5000 - - 87 133