FIELD: finishing and strengthening inner surfaces of cylinders, for example blocks or sleeves of internal combustion engine cylinders. SUBSTANCE: cylinders are treated by steel balls ejected by means of cutting fluid together with false cylinders mounted on ends of cylinders. Treatment is realized by means of ball-torch type tool with the aid of ejection head provided with turbine. Liquid is fed simultaneously to jets and to hydraulic supports. Such treatment eliminates erosion fracture of cylinder edges. EFFECT: enhanced quality of cylinder surfaces. 2 cl, 3 dwg, 1 exp$
