The most clamped devices of tools for lathe are heads of toolholder on a compound rest
with positioning plate in four positions [Rieti et al, 1984].
Tool Post: The tool post is mounted on the compound rest
. This can be any of several varieties but in its simplest form is merely a slotted cylinder which can be moved left or right in the T-slot in the compound and clamped in place.
In the figure below, the tool post is shown mounted on a compound rest
. The rest is a small slideway that can be clamped in any angular position in the horizontal plane and is mounted on the cross slide of the lathe.
You can determine how much is coming off using the compound rest
and locking the carriage to the bed.