The structural use of round timber has been considered competitive in terms of both economics and sustainability due to the low energy consumption required for its processing. However, structural uses of wood in round or sawed forms require knowledge of wood properties, which makes the sorting of these properties essential. The objective of the present study was to determine roundwood grading by ultrassound method. For this evaluation, we tested round timber with different diameters. Static bending tests were performed under the equilibrium moisture content to determine strength and stiffness. Round timbers were sorted using Brazilian standard (NBR 15521 2007). An analysis of the results led to the conclusion that the classification of round timber must consider the range of diameters of the pieces. The classes proposed by the Brazilian standard can be used in the classification of round Eucalyptus timber with the application of a speed correction coefficient. The correction coefficient decreases as the diameter of a round wood increases.