PURPOSE: To automatically position a traveling side saw-tooth guide arm at a proper position according to the width of a material to be cut by moving the traveling vice of a main body vice device according to the width of the material to be cut, clamping the material to be cut, traveling the traveling side saw-tooth guide arm, and detecting a detection plate through a detection sensor.

CONSTITUTION: A proximity switch 51 detects a detection plate 49, and a traveling side saw guide arm 11 is at an appropriate position according to a traveling vice 5M. When a solenoid SOL1 is turned on in this condition, the traveling vice 5M moves to the right with a hydraulic cylinder 13, so that the proximity switch 51 is turned off. As the same time when the proximity switch is turned off, a solenoid SOL3 is turned on until the proximity switch has turned on, the traveling side saw-tooth guide arm 11 moves to the right and is located automatically at an appropriate position. As a result, the traveling vice 5M moves to the right or left according to the width of a material to be cut to clamp the material to be cut and move the saw-tooth guide arm 11 to the right or left.