PURPOSE: To enhance the producibility by omitting works of handling irregularly dimensioned materials.

CONSTITUTION: The length of each steel bat with the leading extremity cut away is measured, and the tail part of the bar is cut with a length which is several times as large as the preset length of the steel bar when it us finish processed, and the length of steel bar after its tail part is count away is measured to serve for correcting of the tail cutting length. The arrangement is equipped with length measuring sensors 4, 10 coupled with a roll rotating in tight attachment to the steel bar transported, end part sensors 5, 8 installed a certain distance apart from a tail part cutting device ahead and behind the same, and a control means which cuts the bar tail when the preset length is attained by the length from the leading extremity of the bar whose leading extremity was cut off and length is measured by the length measuring sensors. The period of the cut bar passing the end part sensor 8 installed behind is measured by the length measuring sensor 10, and the specified length set with this measurement is allowed to undergo a correction automatically.