Check sheaves for cleanliness, damage and wear each time belt maintenance is performed and whenever belts are changed. The inspection procedure is described on page 7 of this guide. Use the Groove Dimensions Tables 1 and 2 (on pages 3-6) and tolerance data below as a reference to determine if excessive sheave wear has occurred. They can also aid in replacement belt cross section selection, if necessary. The tables are based on industry standard dimensions for V-belt sheaves. Always check the original sheave specifications if possible. Variances from industry standards can occur to provide for special design or performance requirements.