The initial physical engagement between a machine tool and the raw material being processed. Operators carefully monitor this moment to establish a zero reference point before beginning a heavy cut or automated sequence. A harsh or unexpected engagement can shatter carbide inserts, ruin the surface finish, or throw the machine out of alignment.
Heard on the job
Bring the spindle down slowly in manual mode until you get contact with the top of the block.
Also heard as
- touch-off