Cast iron lathe chuck backplate adapter fits lathes with 1/2"-20 spindle nose thread
Adapter is 3" (80 mm) in diameter and has three chuck mounting holes for a 3-jaw chuck
For 3" 3-jaw chucks
Includes instructions for final turning of the registration diameter to insure concentricity
This adapter is for a 3" 3-Jaw chuck such as LittleMachineShop.com PN 1187. *NOTE* These adapters require machining on the lathe on which they will be used. Instructions are included for final turning of the registration diameter on your lathe to insure perfect concentricity.