Resumo. The objective of this paper was model the shape, compare the efficiency of the total volume estimated with the 5th grade polynomial, with and without data stratification by an artificial form quotient and build the assortment table. The data came from Pinus taeda L. stands, managed by a sawmill company, with two thinning and coppicing, plantation of 1.600 trees/ha and spacing of 2,50 x 2,50 m, from Klabin S.A., in Telêmaco Borba, Paraná state. The field data was stratified in three form quotient classes defined by the diameter of 70% total height and breast height diameter. The trunk classification in assortments was accurate and the volume obtained with the integrated equations presented small residues, without tendency. The results proved the viability of the data stratification by form quotients to obtain better estimative of tree assortments.