crossfeeds are geared differently than longitudinal feeds. on most lathes the crossfeed is approximately one-half that of the longitudinal feed, so a facing job () with the quick-change gearbox set at about .012 feed would actually only be .004 for facing. the crossfeed ratio for each lathe is usually found on the quick-change gearbox index plate.
the half-nut or split-nut lever on the carriage engages the thread on the lead screw directly and used only for threading. it cannot be engaged unless the feed change lever is in the neutral position
both the crossfeed screw handle and the compound rest feed screw handle are fitted with micrometer collars () these collars traditionally have been graduated in english units, but metric conversion collars () will help in transition to the matric system.
some micrometer collars are graduated to read single depth: that is, the tool moves as much as the reading shows. when turning a cylindrical object such as a shaft, dials that read single depth