I read about this in Model Engineer's Workshop magazine and thought I'd give it a try. Using a Rawlplug De-Speeder in the tailstock of the lathe to tap into mild steel, brass or aluminium. Brilliant. No more broken taps.
Many thanks to Sleykin who explained that these were designed to allow you to use a power drill to drive in screws when power drills only had one speed.
Music by Kevin MacLeod.
