turning small shaft 4140 (hardening + tempering) on TOS SN 50B lathe

While working on a small project I tried to capture video about turning small drilling shaft from chromoly on my TOS lathe. Subtitles will be added soon.

[@836dmar]

Did you turn do final turning after after hardening due to possible dimensional changes from heat or surface finish or both? I've read many 4140 parts put into service without tempering and this looks like such an application.

[@cyrildanko8422]

Part was also tempered, but unfortunately that's not captured in the video. I always leave some material before HT, finished part should be machined on cylindrical grinder for best tolerances.