What tolerances and surface finishes can be achieved?

The absolute tolerances which we can supply to will be dependent on the size of the part and the machining method used. For CNC machining, tolerances better than ± 0.05 mm are possible. With EDM, these are typically ± 0.02 mm. Flatness to within 1 in 1000 is usual. Surface finishes after milling are normally to Ra < 1μ, but with lapping this can be improved to Ra < 0.4μ.