Tolerance in mm

n ≤ 16

n > 16

ordinary

$4\ast \sqrt{36\ast L+L^2}$

$\sqrt{36\ast N+N^2/16}$

accuracy

$4\ast \sqrt{9\ast L+L^2}$

$\sqrt{9\ast N+N^2/16}$

High accuracy

$8\ast \sqrt{L}$

$2\ast \sqrt{N}$