Manual

58
4 x BD 3 x BD 3 x BD
6 x BD 5 x BD 5 x BD
10 x BD 5 x BD* 5 x BD*
14 x BD 7 x BD 7 x BD
3. Turning
Bar types
Internal turning is very sensitive to vibration. Minimize the tool over-
hang and select the largest possible tool size in order to obtain the
best possible stability and accuracy. For internal turning with steel
dampened boring bars, the rst choice is bars of type 570-3C.
For grooving and rough threading operations where the radial forces
are higher than in turning, the recommended bar type is 570-4C.
The table below shows the maximum recommended overhang for
different bar types.
The static stiffness of a carbide reinforced bar is improved by about
2.5 times compared to a steel bar with the same overhang.
Bar type
Steel boring bars
Turning Grooving Threading
Carbide boring bars
Steel dampened
boring bars
Carbide reinforced
dampened boring bars
* 570-4C bars
There are different dampening systems for different overhang
lengths: