| 摘要 |
PURPOSE: A manufacturing method of T-type bearing bars for a steel grating material is provided to improve working productivity and more reduce manufacturing cost of the bearing bars by improving a manufacturing method of bearing bars having a "T" type cross section, and a steel grating manufactured by using the method is provided. CONSTITUTION: In a manufacturing method of bearing bars which are arranged on a steel grating with the bearing bars being spaced apart from each other in a certain distance, the manufacture method of T-type bearing bars for a steel grating material comprises preparation step (S1) of preparing a metal wire rod having a rectangular cross section in which a widthwise width is wider than a lengthwise width; rolling step (S2) of gradually reducing thickness of the metal wire rod and extending a cross-sectional length thereof at the same time by rolling one side portion of the metal wire rod prepared in the preparation step (S1) in multistage, and forming a flange surface on the other side portion of the metal wire rod so that the metal wire rod has a "T" type cross-section; and cutting step (S3) of cutting the metal wire rod having the "T" type cross-section through the rolling step (S2) to a certain length, wherein not only upper and lower surfaces of the one side portion of the metal wire rod are rolled by upper and lower rolling rolls, but also an end part of the other side of the metal wire rod is rolled by a side surface rolling roll to form the flange surface in the rolling step (S2).
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