The SHERLINE chuck is designed so that it can be used to clamp externally on bar stock or internally on tube stock. The P/N 1041 chuck is designed to grip from 3/32" (2mm) to 1-3/16" (30mm) diameter stock with the jaws in the normal position. The P/N 1040 chuck handles stock up to 1-1/2" (38mm) in diameter. For larger diameter work, the jaws must be reversed (See Figure 2). The reversible jaws can grip to 2-1/4" (56.0 mm) for the P/N 1041 chuck and up to 2.75" (70 mm) for the P/N 1040 chuck. The chucks have a .687" (17mm) diameter through hole with a 3/4"-16 thread.
Due to the nature of the design of a 3-jaw chuck, it cannot be expected to run perfectly true. Even 3-jaw chucks costing five times more than the one made for this lathe will have a 0.002" to 0.003" runout. If perfect accuracy is desired in a particular operation, the use of a 4-jaw chuck or a collet is recommended. Both are available for your SHERLINE Lathe.