For a shaft measuring one inch in diameter with an RC6 sliding fit, what is the allowance?

A shaft specified with an RC6 sliding fit indicates a certain degree of looseness between components, which is measured in terms of allowance. The allowance refers to the intentional difference between the dimensions of the mating parts, in this case, the shaft and the hole it fits into.

For an RC6 fit, the allowance is negative, which means the diameter of the shaft is smaller than the specified dimension for the hole it fits into. This specific sliding fit type is designed to ensure that the shaft can easily slide within the hole without much resistance, characteristic of an RC (running and sliding) fit.

In the case of a one-inch diameter shaft with an RC6 fit, the standard allowance calculated is -0.003 inches. This means the actual diameter of the shaft is marginally less than the nominal size, facilitating smooth operation. It's important for applications where a degree of movement between the parts is necessary for functionality, such as in rotary applications or assemblies where thermal expansion may also need to be considered.

This understanding of how tolerances and fits function is crucial in manufacturing and mechanical design, as it directly influences assembly quality and functionality.