PURPOSE: To produce a good gear in reverse rolling by detecting the position in front of the front extremity of an advancing movable die and stopping it and thereby making the diameter greater than final finish pitch diameter.

CONSTITUTION: Out of a pair of rolling dies 1A, 2A, advancing of a rolling die 1A of movable side is detected by a position detector 26 at any position in front of mechanical front extremity. Then, high pressure in a cylinder 22 of the rolling die 1A is changed to low pressure and the rolling die 1A stops without moving forward or backward. It performs warming up operation for a while to stabilize the effective diameter of the gear 31. Then, it stops rotation and prepares for the next reverse rolling.