Breaker for radial tire

A pneumatic tire for motor vehicles comprising a carcass, a tread band and a reinforcing annular structure inserted between said carcass and said tread band, said reinforcing annular structure comprising at least three layers of metal cords, said layers being substantially as wide as the tread band, two layers which are arranged in a radially inner position with respect to the third layer comprising metal cords having an ultimate elongation of about 3%, said metal cords being parallel to one another in each layer and crossed with respect to those of the other layer, said cords in said two layers being symmetrically inclined with respect to the longitudinal direction of the tire and forming an angle between 5.degree. and 30.degree., the third layer being arranged in a radially outer position and comprising metal cords having an ultimate elongation between 4% and 8%, the cords of said third layer being substantially parallel to one another and arranged substantially parallel to the longitudinal direction of the tire, said third layer consisting essentially of a central portion extending astride of the center line and having a width between 40% and 80% of the total width of said layer, and two lateral portions extended side by side with said central portion, each of said lateral portions having a greater resistance to tension and compression stresses than that of said central portion.