Fits and Tolerances

Every shaft collar and rigid coupling we produce at Ever-Power Group Co. Ltd. is machined for precision and accuracy to provide unrivaled consistency in fit and function. The dimensional tolerances described below apply to our standard products. Our team is capable of providing ultra-precision products to tighter tolerances as needed for specialty applications.

The Inside Diameter (also ID or bore) of our collars and couplings is designed for a smooth slip-fit over industry standard shafts to ensure optimal seating and clamping. The specific tolerances vary depending on size and measure between 0.001" and 0.005" over the nominal size. The Width of our collars is assured to be within ±0.005" for smaller sizes and ±0.010" for larger sizes, and the Length of our rigid couplings is held to dimensional tolerances of ±0.015". The Outer Diameter of both collars and couplings is held to within ±0.015" of the specified dimension.

An indicator on the outside diameter of a properly mounted collar should show a total run-out of no more than 0.010". An indicator on the Face of a properly mounted EP collar should show a total run-out or out-of-flat be no more than 0.005" for small parts and 0.015" for large parts.

The Concentricity of our couplings is determined by measuring the total indicated run-out when one end of the coupling is mounted on a shaft known to have "0" run-out and an indicator is placed on the surface of a properly mounted shaft located one inch from the opposite face of the coupling. In this configuration, the total indicated run-out of the second shaft should be less than 0.002" for small parts and less than 0.004" for large parts.

For additional information about fits and tolerances, or to discuss a custom product, contact us directly.