For inspecting the straightness and flatness straightness&flatness of working surfaceparallelism between Working surfacessquareness between Working surface and side surfaceTYPE(mm) precision grade(um) 000000000400x60x251.62.62.43.98.013630x100x352.13.53.25.310.5181000x160x503.05.04.57.515251600x250x804.47.46.611.122372000x300x1005.4108.113.52745