Manufacturing equipment for electric resistance welding pipes having excellent characterization for welded seam

Manufacturing equipment of electric resistance welding pipes having excellent characterization of welded seams, comprising:

• an apparatus that supplies a strip,
• an apparatus that reforms a shape,
• an apparatus that performs roll forming,
• an induction heater, and
• a contacting apparatus of strip edges by pressing, and having an apparatus for cutting or stone-grinding the strip edges or a hole-shape roll after the apparatus for reforming the shape, and a finpass forming apparatus incorporating a fin having at least two stages of edge tapering in the middle of the roil forming, wherein tapering edge of the strip immediately before electric resistance welding is conducted such that an angle from a surface of an edge of the strip toward a vertical direction is in a range of 25 degrees to 50 degrees, and length of a perpendicular angle from a starting position to an end position of the edge tapering at one side is 20% to 45% of strip thickness, and by shaping the edge tapering with a fin, having at least two stages of edge tapering, incorporated in a finpass forming end stand.