METHOD OF ROLLING DEFORMED BAR AND ROLL FOR DEFORMED BAR

摘要

A steel bar for concrete reinforcement having knots and four ribs on its surface is produced by performing the final finish rolling by means of a two-roll rolling mill. Rolls R1, R2 of the two-roll rolling mill have a roll caliber (3), round calibers (2) and a bottom groove (1). The roll caliber (3) is substantially semi-circular in cross section, and is provided over the whole peripheral surface of the roll. The round calibers (2) are made in the groove surfaces of the roll caliber (3) and have a predetermined width so as to cross the roll caliber (3). The cross section of the bottom groove (1) is an isosceles trapezoid and the groove (1) is provided along the center line of the roll caliber (3) over the whole circumference of the roll caliber. <IMAGE> <IMAGE>