Patent ID: 6845560

Claim:
A method for manufacturing a hollow rack shaft comprising: a first step for forming a substantially flat and rectangular plate workpiece into a gutter-like shaped workpiece, said gutter-like shaped workpiece has a flat bottom portion, a pair of semi-circular bottom portion extending from each longitudinal side of said flat bottom portion, and a pair of leg-like side wall extending upwardly in parallel from each lateral side of said flat bottom portion and said semi-circular portions; a second step for forming a row of rack teeth on said flat bottom portion of said gutter-shaped workpiece; and a third step for forming said workpiece into a hollow shape by bending said leg-like side walls by butting edges of said walls each other; wherein a pressing surface of a pair of dies used in said first step is inclined in a longitudinal direction of said workpiece relative to a pressing surface of a second pair of dies used in said first step so as to cancel elastic recovering of said workpiece when said workpiece is removed from said die set.