This standard describes and defines variations that may occur in unassembled wormgearing. It displays measuring methods and practices@ giving suitable warnings if a preferred probe cannot be used. The applicability of single or double flank composite testing is discussed@ using a reference gear. Tooth thickness measurement is shown using direct measurement as well as the use of measurements over wires or pins. Equations for the maximum variations are given for the stated ranges@ as a function of size@ pitch and tolerance grade.