I use one of the Mini-Thin holders from MSC (sorry JS) as they often have them on special offer. does neutral, L/H and R/H parting as well as square bottom/round bottom grooves of various sizes and threading. They work very well, I originally bought it for doing E clip grooves, here it is putting in 1mm groves for piston rings.

You can buy the tips and screw separately so could make a holder quite easily if so inclined.
J
Edited By JasonB on 08/08/2014 07:29:55