Post-forming method and apparatus

A method of rolling a bar consisting of steel or alloy steel,

• wherein said method comprises the step of passing the bar consisting of steel or alloy steel through at least one roll stand configured to roll a bar consisting of steel or alloy steel to thereby form a rolled bar, wherein the rolled bar has a central longitudinal axis and three interconnected arms, each of which extends along the central longitudinal axis and generally radially from the central longitudinal axis adjacent one another, and wherein each of said three interconnected arms are from 2.0 mm to 4.0 mm thick,
• wherein the roll stand comprises:
• only three roll assemblies for shaping said arms, with each said roll assembly comprising:
• a roll having an axis of rotation and a circumferentially extending contoured rim extending between any two adjacent bar arms,
• a roll positioner for moving the roll towards or away from the pass line, and
• a drive shaft extending from the roll;
• wherein the roll assemblies define a pass line along which the central longitudinal axis of the bar substantially travels;
• and
• wherein the rolls are spaced about the pass line with their said axes of rotation in a common plane and said contoured rims provide a void through which the pass line extends and shape the arms of the bar as the bar passes through the void, and
• wherein the roll positioners are capable of moving the rolls incrementally within the common plane and along an axis perpendicular to the axis of rotation of each said roll so as to change the size of the void;
• and
• wherein the rolls abut each other to thereby encapsulate the bar as it passes through the void;
• and
• wherein the method comprises the step of varying the rotational speed of at least one roll within any one roll stand independently of the rotational speed of another roll within the any one roll stand;
• and
• wherein the at least one roll stand is a plurality of roll stands arranged in sequence, wherein the rolls of each of said roll stands have circumferentially extending contoured rims adapted to incrementally form the three interconnected arms of the rolled bar.