HEIDENHAIN AK ERA 4x80 Instructions De Montage page 6

When mounting the scanning head and the scale drum, please refer to the dimensions and notes in the
Mounting Instructions for the respective ERA 4x0x Scale Drum.
All mounting surfaces must be clean and free of burrs.
The specified shaft tolerances must be complied with.
The scale drum is to be fastened with all provided screws and washers.
The screws must be tightened with the specified tightening torque according to the Mounting Instructions,
and secured against unintentional loosening.
Only then are the speed values specified for the scale drums valid.
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