Small BS-0 ctr drilled hole in the end and use your tailstock ctr to support the work, can be made over length and the bit with the hole in turned off if you don't want the hole to remain. Do all my IC engine valves this way which is the same sort of process.

Edited By JasonB on 15/05/2019 07:44:08

Just turned on my computer after spending the afternoon making valve spindles.

These are for 6mm globe valves and made from 316 stainless. The round bar was held in a collet chuck (more accurate than my 3-jaw) with only a small amount protruding from the chuck to prevent any bending. Each section turned to size and the spindle extended a bit further in the chuck to do the next section.  The small end then threaded M3 and the larger M5.  The spindle then cut from the bar stock.  I then changed collets and held the spindle by the M5 thread to finish turning the head end.

Paul.

Edited By Paul Lousick on 15/05/2019 07:26:25