Optomechanical assemblies are e.g. objective lenses built in a holder: There are no general tolerances available because each single assembly of these interdisciplinary products are worked out individually.
Achievable tolerances
true running 0,002
"centering tolerance" "4 / 1‘ (depending on radii) " "cement wedge" "4 / Δ 1‘ (depending on diameter, radii, cement)"