PURPOSE: To decrease stages and to obtain patterned flat bars of beautiful finishes at a low cost by rolling heated ingot iron by using patterned rolls while hot.

CONSTITUTION: Heated ingot iron 1 is subjected to the primary rolling with rolling rolls 2, 2' to an intermediate flat bar 3. Patterns 6, 6' are beforehand provided on the surface of a rolling roll 4 of the rolling rolls 4, 5 for the secondary rolling, and while the intermediate-rolled flat bar 3 is hot, the bar is passed between the rolls 4 and 5 to form the patterns 8 on the surface of the flat bar 3. By the above-mentioned method, the patterned flat bar 7 of beautiful finishes are produced without any production loss. The patterned iron flat bar is used for handrails, fences, etc.