The effect of conditions and routes of deformation in the course of equal-channel multiple-angular extrusion (ECMAE) on physical and mechanical properties of polyoxymethylene (POM) have been studied. As deformation routes, Route C (shear planes are parallel, and the simple shear direction of every deformation zone is changed through 180 degrees) and Route E (shear planes are turned through +/- 45 degrees around the extrusion axis and the normal to the axis, and simple shear direction is changed through 180 degrees or +/- 90 degrees with respect to the deformation zone) were selected. It has been shown that ECMAE provides the increase of modulus of elasticity E more than twice, tensile strength sT increases in four times. At the same time, strain at break eb is reduced by 1.5%. The value of the achieved effects depends on the accumulated deformation and the selected deformation route. The best set of physical and mechanical characteristics was observed in the case of Route E. According to SEM data, Route C results in partial pore healing and E provides total pore healing both in longitudinal and transversal direction. The observed effects are related to orientation order formation, increase of cristallinity degree and reduction of structure imperfection of extrudates. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012