Abstract: A shaft/roller unit for tracked vehicles which has a long life and resistance to wear is formed by a shaft (54) which has a shoulder (55) in its central portion, perpendicular to its axis, and onto which two wholly hardened steel half-rollers (56, 57) are fitted, one on each side of the shoulder, with the interposition of antifriction bushings (58, 59), the half-rollers grasping the shoulder (55) and, when they have been welded together along a mating contact and locating surface (60), forming a unitary roller which has a predetermined axial position on the shaft and can withstand considerable axial stresses.

Abstract: A method of manufacturing a first connecting link and a second connecting link from an individual forging which can be juxtaposed along a predetermined profile to form an openable link for joining a chain of links into a closed loop to form a track comprises the steps of providing the individual forging of the openable link, securing the forging in a cantilevered position on a work table, and cutting the forging along the predetermined profile from one side to the other side of the forging by spark-erosion machining with a wire so that the first connecting link and the second connecting link are provided with juxtaposed, sided by side cut surfaces, where the first connecting link is formed and separated from the second connecting link leaving the second connecting link secured on the work table in a pre-determined position.