Precision ERW tube molds and mill rolls that shape flat steel strip into welded tube — round, square and rectangular — pass after pass, at full line speed.
Every ERW line is only as good as its tooling. HUAQI designs and machines the full roll set for your mill — profiled to your tube size, wall thickness and steel grade.
The first stands do the heavy work — bending flat strip step by step into an open tube without stretching the edges, so the weld seam closes clean and straight.
The final forming pass guides the open seam into the high-frequency welder and squeezes the heated edges together — where tube quality is won or lost.
After welding, sizing stands calibrate the tube to its final outside diameter and tolerance — or convert it from round into square and rectangular profiles.
Four-roll Turk's heads take the bow and twist out of the finished tube and can fine-profile special shapes — the last touch before cutting and stacking.
An ERW line never stops moving. Steel strip feeds in flat and leaves as finished welded tube — our molds control every millimetre of that journey.
Breakdown and cluster rolls curl the strip edges upward pass by pass. The profile of every roll is ground to a calculated flower pattern, so the strip forms evenly with no edge wave or cracking.
Fin-pass and squeeze rolls present the edges to the high-frequency induction coil at the exact vee angle. Heated to forging temperature, the edges fuse into a seam as strong as the parent steel.
Sizing rolls and the Turk's head bring the welded tube to final diameter, squareness and straightness. The result: tube that stacks, ships and sells as a precision product.
Rolls live a brutal life — abrasion, heat and tonnes of pressure. HUAQI machines every mold from proven tool steels, hardened and precision-ground.
The core of every ERW line — water, gas, structural and mechanical tube.
Formed direct or converted from round in the sizing section.
Hollow sections for construction, furniture and automotive frames.
Oval, D-shape and custom profiles designed from your drawing.
Tell us your tube size, wall thickness and mill model. We'll spec the roll set — forming, fin-pass, sizing and Turk's head — for your line.