Manufactured from high alloy steel hardened and tempered then precision ground externally. Precision bearings are fitted as standard and the centres have a 60? point. Mounting Tapers are accurate to DIN228 Form A, Tolerance Class AT5. | | Maximum runout: | No.1 to 4 taper: 0.005mm. | No.5 to 6 taper: 0.010mm.