Abstract: In a multipart cooled piston (20) for a combustion engine with a piston upper part (1) of steel comprising a combustion bowl (3) and a ring wall (4) with ring belt (11), and with a piston lower part (2) comprising a piston skirt (9), pin bosses (12) for receiving the piston pin connecting the piston (20) to the connecting rod, and pin boss supports (6) connected to the piston skirt (9), and in a method for manufacture of such a piston (20), inexpensive manufacture and good form stability are to be achieved in that a cooling channel (7) formed inside the piston upper part (1) has forged supporting ribs (8) in its area extending to the combustion bowl (3), which each form sections of an all-round ring rib (5) with a connection surface radially to the longitudinal piston axis (K), in that the piston lower part (2) has an annular and all-round carrier rib (10) with a connection surface connected to the pin boss supports (6), and in that the piston upper part (1) and the piston lower part (2) are non-detachably co

Abstract: Method of manufacturing, in one piece, forged connecting rods. The method includes cutting blanks from a bar. Each blank is worked in several steps, until it assumes its final shape. During the various working steps, a groove made in each blank is caused to spread out in a predetermined manner and finally forms a fracture initiation (44), in the area (38) through which bolt holes are drilled for the bearing cap mounting bolts. After final working, the remaining portions of the core portion (10, 46, 50) are divided by a slight separating force, thus providing in the fracture surface the required guidance for remounting the bearing cup on the upper bearing.