- The production process of Sharp Corner Hollow Sections (SCHS) mainly uses cold bending and high-frequency welding (accounting for more than 90% of the market), with only large-diameter, thick-walled, or special material products being made using hot rolling. Among these, the core of the cold bending process is to achieve sharp corners with a small inner radius (r ≤ 1.5t) by multiple stages of progressive deformation and extrusion with precision sharp-corner forming molds.
- Cold Forming：Uncoiling → Leveling → Slitting (optional) → Preliminary forming (arc U-shape / C-shape) → Fine forming (sharp angle extrusion) → High-frequency welding → Sizing → Straightening → Flying saw cutting → End face treatment → Inspection → Subsequent processing → Packaging and warehousing
- Hot Roll Forming：The raw material is continuously cast billets→ Heated to a plastic temperature of 1200~1300°C →Hot rolled forming(No welding required) → Sizing and Cooling (Air cool or water cool to room temperature) → Cutting and Processing
Core comparison of the two processes
| Cold Forming + High-Frequency Welding | Hot Roll Forming | |
| Applicable Specifications | 20mm≤O.D≤500mm , 0.8≤W.T≤20mm | O.D≥200mm, W.T≥10mm |
| Inner corner radius | r≤1.5t,High sharpness of the tip | r≈1.5 / 2.0t, The sharpness of the tip is average |
| Dimensional accuracy | Height (side length tolerance ±0.5mm) | Low (edge length tolerance ±1.0mm) |
| Surface Quality | Smooth, no oxide scale | Rough, with oxidation scale, requires pickling treatment |
| Production cost | Low (high degree of automation, high material utilization) | High (high energy consumption, low material utilization) |
| Application Scenario | Building curtain walls, equipment racks, decorative works, automobile chassis | Large steel structures, bridge supports, and construction machinery chassis |
Applicant Field
| Field | common choice | |
| Construction steel structure | Used for frame columns, braces, and truss structures |
Bending and torsional strength superior to round pipes and angle steel of the same specifications
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| Vertical frames, horizontal frames, and keel of the glass curtain wall |
The right-angle design of the sharp-corner square and rectangular tubes can perfectly fit the right-angle framework of the curtain wall.
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| The load-bearing framework of the house, wall studs, and roof purlins |
The sharp-cornered rectangular and square tubes have high dimensional accuracy and allow for modular assembly.
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| Machinery Manufacturing Industry | Frames and bases of CNC machines, injection molding machines, and printing machines |
The sharp-cornered square and rectangular tubes have good rigidity, effectively reducing equipment operation vibration.
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| Frames and guide rails for belt conveyors and automated production lines |
The right-angle design of the sharp-corner square and rectangular tube makes it easy to install components such as rails and sliders, while providing stable support.
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| The undercarriage, frame, and working arm of equipment such as excavators |
The high strength of the sharp-cornered rectangular tube can withstand heavy loads and impacts from equipment.
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| Furniture and Decoration Industry |
Frames of metal furniture such as desks, chairs, sofas, and beds
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Can create a minimalist and modern furniture style while providing sufficient support strength |
| Glass partition frames in shopping malls, stair railings in villas |
Aesthetic appearance and flexible design requirements
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| Solar mounting system | Support frame for solar photovoltaic panels |
Square and rectangular tubes have high strength and can withstand the weight of photovoltaic panels and wind loads.
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| Naval Architecture and Ocean Engineering |
Deck frames and bulkheads for ships
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| Electric power equipment industry |
Crossarms for high-voltage transmission towers and equipment brackets for substations
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need hot dip galvanized tube |
