Durston 1501 Steel Plain Round Bezel Mandrel 10mm to 28mm

Plain round bezel mandrel from Durston Tools. the smallest diameter is 10mm (3/8") round with the largest diameter 28mm (3/8").  Total length is 

This mandrel is used for just about any type of round forming work you would want to do with non-ferrous metals like gold, silver and brass.