For one of my new restorations (antique stapler), I need rivet headers for my arbor press. I turned them on my lathe from 34CrNiMo6 hardening steel. I slightly went less deep as normal with the hole in the headers to make sure, the headers won’t touch the mirror finish of the stapler later on. After the turning I hardened it with a two step heat application. First hardening was achieved by heating it up to around 850 degrees c, after quenching in oil, I started the second called tempering treatment.