The English-made Burnerd "Multi-size" collet chuck is an all metal structure, superbly made and available with both lever-action and key-driven collet closers in a range of spindle-nose fittings.
Each collet adjusts over a range of sizes and can be minutely set to correctly hold any size of bar - be it a "from-stock" inch or metric item - or specially made. Of all the various collet types on the market, this is the one that provides the skilled centre-lathe operator with greatest versatility. If you can find one to fit your own lathe - buy it.