What is a tolerance block used for in machining?

A tolerance block is used in machining to indicate acceptable deviations from specified dimensions for a part. Tolerances are crucial in manufacturing because they ensure parts fit and function together correctly. They define the allowed variation from the nominal dimension, which is the ideal measurement for that particular part. By specifying these acceptable limits, manufacturers can maintain quality control and ensure that parts meet design requirements despite natural variations that occur during the manufacturing process. This is particularly important in precision machining, where even small deviations can affect assembly and performance.