All centre grinders by technica technology grind geometrically round centre holes with an achievable centre hole roundness of ≤ 1 µm. The Zentroflex by technica technology can grind geometrically aligned centre holes with centre hole axle alignment of < 10 µm. Surface roughness of the centre hole: N4 – N6 / Ra 0.2 – 0.8 / Rz 1 ...