Material typeFor hot rolled steel, forgings, and molded parts, standard jaw chucks tend to be more effective because all of these parts have inherent diameter variations. On the other hand, cold roll material parts tend to have better dimensional consistency, so spring chucks are suitable for use. However, the lack of consistent diameter measurements does not necessarily constitute a barrier to spring-loaded chucks, and chucks designed for non-circular cross-sections are available for clamping molded rods made into the shape required by the customer.
Spindle load capacity The large allowable weight of the lathe spindle is based on the bearing load capacity, and if the weight of the chuck and workpiece combination is too large, the bearing may be overloaded. For machining tasks where there is a danger of exceeding the limit, this danger may determine the choice of workholding, and the jaw chuck is often heavier than the equivalent spring chuck, so the spring chuck is the appropriate choice in the case of weight control.
Workpiece size spring chuck is ideal for workpieces less than 3 inches in diameter. The spring chuck limits the length of the workpiece, in particular, the spring chuck limits the axial (Z-axis) travel range of the machine because its length is longer than the jaw chuck. When the machining length of the workpiece requires almost the entire usable stroke of the machine, the jaw chuck is probably used.