Composite materials are widely used in mechanical engineering, but at edge cutting machining, in particular, during milling these materials a number of peculiarities arise which must be taken into account at the definition of cutting modes and design-geometrical parameters of cutters. Besides, new composite materials machining does not allow using effectively the recommendations developed earlier. In such a way, to solve such a problem it is necessary to carry out experimental investigations on the analysis of the influence of milling mode characteristics and design-geometrical of a tool upon values of roughness of a surface processed and tool wear. As a cutter for investigations there were taken hardmetal endmilling cutters of TC-8 (tungstencobalt) type, the experimental samples – pipes made of composite material with oblique longi-tudinal-transverse fiber winding (OLTFW). As varied parameters were adopted cutting modes: cutting speed V, m/min, feed S, mm/tooth and milling depth t, mm. During the experiments were controlled the following parameters: tool wear Δ, mkm, roughness of the surface Ra, mkm and a depth of a faulty layer h, mkm. To carry out the experiments there was offered an original design of an assembly milling cutter which allows defining in an experimental way optimum geo-metrical parameters of a tools to achieve output milling parameters specified. On the basis of experiments data there are obtained dependences allowing the estimate of parameter modes influence upon the period of cutter duration at the same time a temperature is affected mostly by a milling depth and a feed on a tooth affects the wear of an end flank.