METHOD OF MAKING STEPPED HOLES IN THE PARTS Russian patent published in 1994 - IPC

FIELD: mechanical engineering. SUBSTANCE: hole is partially filled with insert on side opposite to the force being applied. Circular projection is formed by pressing-out on side of the step at the diameter equal to diameter of the step forming simultaneously the strengthened layer and blind chamber above the end of the insert. Then applying the axial compression force to the end of the circular projection, chamber is filled forming the bearing surface of the step, after which insert is removed and axial force is applied to the bearing surface of the step. EFFECT: enhanced efficiency. 7 dwg