This SAE Recommended Practice contains dimensions and tolerances for spindles in the interface area. Interfacing components include bearing cones, bearing spacers, and wheel hubs. This document is intended for axles commonly used on Class 7 and 8 commercial vehicles. Included are SAE axle configurations FF, R, N, and P. SAE configurations FC, FL, K, L, U, and W are not included, but may be added in the future.