In CNC machining, what does the term 'tolerance' mean?

The term 'tolerance' in CNC machining refers to the permissible limit of variation in a dimension. Tolerance defines the acceptable range of dimensions that a manufactured part can have, ensuring parts fit together correctly and function as intended. When parts are produced, it's not always feasible to create them to the exact measurements every time due to factors like machine wear, material properties, and other environmental influences. Therefore, specifying tolerances allows for some leeway in dimensions while maintaining the necessary function and compatibility of the parts.

In contrast, the other options describe different aspects of CNC machining. For instance, the speed at which the machine operates relates to the feed rate and spindle speed during machining but does not concern dimensional accuracy or fit. The type of milling strategy employed pertains to the approach used for cutting the material, such as contouring or pocketing, rather than how dimensions are measured or defined. Lastly, the weight of the workpiece being machined can affect the machine settings and stability but does not relate to the concept of dimensional variation or tolerance.