 All axes are indexed to .0001" via a vernier scale on the handwheels, with higher accuracy available with the use of measuring bars.The machine head has two vertical travels, one rough head adjustment and the other a precise spindle adjustment.To change the diameter of the hole to be ground the air spindle can be offset from the axis of the rotary head by a slide in a similar manner to a boring head for a milling machine, allowing a hole of any size to be ground with the same tooling (up to the machine's capacity).