Direct Square Forming Tube Mill: LW120-LW2000
Cold bending profile steel and square/rectangular pipe line is the equipment used for production of open-mouthed and close-mouthed profile steel. With combined type of rollers, and multi points pre-bending forming technology, rollers can be changed quickly with no necessary to remove main axis or stands. Further, with the low loading, it can reduce 80% of rollers cost and 90% of time for changing rollers. All specified open or close mouthed profile steel can be produced with one set of combined rollers. lt is suitable for multi-specification small batch production and meet the market requirement as well.
Great Wall is a professional square tube mill line supplier specializing in direct square forming tube mills for square and rectangular steel tube production. Our DFT tube mill lines use combined roll tooling and multi-point pre-bending technology to support multiple tube sizes with reduced tooling costs and faster size changeover.
DFT tube mill is an industrial production line used to manufacture square or rectangular steel pipes directly from steel strips through continuous roll forming, high-frequency welding, sizing, and straightening processes. Compared to traditional round-to-square forming, direct square forming improves precision and material utilization. As a professional Direct Forming Tube Mill manufacturer, Great Wall offers a complete range of high-performance tube mill equipment for square and rectangular tubes.
The process begins with steel coil uncoiling, followed by leveling and shearing. The strip is then fed into the forming section where rolls progressively shape it into square or rectangular forms. High-frequency induction welding bonds the edges, after which the welded tube undergoes sizing, straightening, cutting, and stacking. Great Wall’s square tube mill lines feature solid-state HF welding, CNC control systems, and automatic adjustment modules to ensure stability and consistency across production runs.
The direct square forming tube mill can process a wide range of steel coils for manufacturing square and rectangular tubes. The forming system can be configured according to material strength, strip thickness, finished tube size and required production speed.
Common materials include:
| Material | Typical Features | Common Applications |
|---|---|---|
| Low Carbon Steel | Good formability and weldability | Furniture, general structures, machinery |
| Q195 / Q235 Steel | Economical and easy to process | Construction, fencing, general structural tubes |
| Q355 Steel | Higher strength and load-bearing capacity | Steel structures, machinery frames, heavy-duty applications |
| High-Strength Low-Alloy Steel | Higher strength with reduced material weight | Automotive, engineering and structural applications |
| Hot-Rolled Steel | Suitable for medium and heavy-wall tube production | Construction and structural tubes |
| Cold-Rolled Steel | Better surface finish and dimensional consistency | Furniture, precision components and decorative tubes |
| Galvanized Steel | Improved corrosion resistance | Outdoor structures, fencing and solar mounting systems |
| Zn-Al-Mg Coated Steel | Enhanced corrosion resistance for demanding environments | Solar structures and outdoor applications |
A DFT tube mill is designed for producing square and rectangular steel tubes in multiple sizes and wall thicknesses. Its flexible forming system is especially suitable for manufacturers serving different industries and handling frequent specification changes.
Typical applications include:
| Application | Typical Tube Requirements |
|---|---|
| Steel Structures | Large square and rectangular tubes with good dimensional accuracy and load-bearing strength |
| Construction | Structural tubes for buildings, warehouses, platforms and support frames |
| Solar Mounting Systems | Galvanized or Zn-Al-Mg coated rectangular tubes with consistent dimensions |
| Machinery Frames | Square and rectangular tubes requiring stable straightness and assembly accuracy |
| Automotive Components | High-strength tubes for frames, supports and structural parts |
| Agricultural Machinery | Multiple tube sizes for equipment frames, supports and protective structures |
| Highway & Guardrail Systems | Structural rectangular tubes for outdoor infrastructure |
| Furniture & Storage Systems | Thin- and medium-wall tubes with good surface quality |
| Logistics & Racking Systems | Square and rectangular tubes for warehouse racks, pallets and material-handling structures |
Compared with conventional forming systems that may require more dedicated roll sets, a direct square forming tube mill is particularly suitable for factories producing:
Multiple square and rectangular tube sizes
Small and medium production batches
Frequent specification changes
Large-size structural tubes
Customized tube dimensions for different customer orders
This flexibility makes DFT tube mills suitable for both general structural tube production and diversified industrial tube manufacturing.
In-house CNC machining, roll forming, and assembly lines
ISO 9001 certified, CE-compliant manufacturing process
Pre-shipment full trial assembly & performance testing
Turnkey service: layout design, training, and after-sales support
Fast spare parts supply & global technical assistance
1,000+ projects delivered across 25+ countries
Great Wall ensures stable performance, fast delivery, and full engineering support for every square tube mill line.
Parameter Display
Product Disaplay
| Model | Tube Size Range (mm) | Wall Thickness (mm) | Tube Mill Speed (m/min) |
| LW320 | 30x30 – 80x80 | 1.0 – 4.0 | 20 – 80 |
| LW400 | 40x40 – 100x100 | 2.0 – 5.0 | 15 – 50 |
| LW600 | 80x80 – 150x150 | 2.0 – 6.0 | 15 – 50 |
| LW720 | 80x80 – 180x180 | 3.0 – 7.0 | 15 – 50 |
| LW800 | 90x90 – 200x200 | 3.0 – 8.0 | 15 – 45 |
| LW1000 | 130x130 – 200x200 | 3.0 – 10.0 | 15 – 30 |
| LW1200 | 170x170 – 300x300 | 4.0 – 14.0 | 10 – 20 |
| LW1600 | 170x170 – 400x400 | 4.0 – 16.0 | 10 – 20 |
| LW2000 | 170x170 – 500x500 | 4.0 – 18.0 | 10 – 20 |
| Model | Suitable Tube Range | Recommended Application |
|---|---|---|
| LW320 | Small square and rectangular tubes | Light structural tubes, furniture tubes, guardrails |
| LW400 | Small to medium square tubes | Construction tubes, frames, fencing |
| LW600 | Medium square tubes | Steel structures, machinery frames, solar brackets |
| LW720 | Medium and large square tubes | Industrial structures, support frames |
| LW800 | Medium and large square sections | Flexible production with higher speed |
| LW1000 | Larger wall thickness and tube sizes | Structural and industrial tube production |
| LW1200 | Large square and rectangular tubes | Heavy-duty construction and steel structures |
| LW1600 | Large-size square tube production | Large structural engineering projects |
| LW2000 | Extra-large square and rectangular tubes | Heavy structural tube manufacturing |
| Problem | Solution by Great Wall DFT Tube Mill |
|---|---|
| Low yield rate from round-to-square forming | Direct forming technology improves yield and reduces scrap |
| Inconsistent welding quality | Solid-state HF welding ensures strong, uniform welds |
| Manual adjustment causing downtime | CNC auto-adjustment enhances setup speed and repeatability |
| Material waste due to poor cutting control | High-precision flying saw systems improve cutting accuracy |
| Scaling production for larger sizes | LW2000 model supports high-capacity and large-diameter tubing |
| Item | Direct Square Forming | Round-to-Square |
|---|---|---|
| Forming Method | Strip directly formed into square/rectangle | Form round tube first, then reshape |
| Tooling Requirement | Combined/shared rolls for multiple sizes | More dedicated sizing rolls required |
| Size Changeover | Mainly roll-position adjustment | More roll replacement and adjustment |
| Tooling Investment | Lower for multi-size production | Increases as size range expands |
| Small-Batch Production | Very suitable | Less economical |
| Multi-Size Orders | High flexibility | Lower flexibility |
| Rectangular Tube Production | Flexible adjustment | More dependent on sizing tooling |
| Forming Load | Lower secondary forming load | Additional load during round-to-square sizing |
| Best For | Multi-size square/rectangular tube production | Stable, long-run production of fewer sizes |
In conventional square tube production, different tube sizes often require additional forming and sizing rolls. As the product range expands, manufacturers need to invest in more roll sets, storage space, maintenance, and changeover labor.
Great Wall's direct square forming tube mill uses combined roll tooling and multi-point pre-bending technology. One set of combined rolls can cover multiple square and rectangular tube specifications by adjusting the roll positions instead of replacing the complete tooling set. This design can reduce roller investment by up to 80% and shorten roller changeover time by up to 90%.
| Cost Factor | Direct Square Forming | Conventional Forming |
|---|---|---|
| Roll Tooling Requirement | Shared combined rolls for multiple sizes | More dedicated roll sets |
| Additional Size Cost | Lower | Higher |
| Roll Storage | Less space required | More tooling storage required |
| Changeover Labor | Lower | Higher |
| Changeover Downtime | Shorter | Longer |
| Best Production Type | Multi-size, small and medium batches | Long runs with fewer sizes |
For manufacturers producing many square and rectangular tube sizes, tooling cost is not limited to the initial roll purchase. Roll storage, maintenance, handling and production downtime also contribute to the total operating cost.
With direct square forming technology, fewer roll sets are required and size changes can mainly be completed through roll-position adjustment. On models such as the LW2000, the combined mold system allows electric adjustment without changing the rollers, further simplifying production changeover.
This makes a direct square forming tube mill especially suitable for factories handling frequent specification changes, diversified customer orders and small-to-medium production batches.
Traditional square tube production usually forms a round tube first and then reshapes it into a square or rectangular tube. This process may require more rollers, longer adjustment time, and higher tooling investment.
Direct square forming technology reduces unnecessary forming steps by shaping the steel strip directly into square or rectangular profiles. This helps improve corner accuracy, reduce material stress, and support faster production adjustment for different tube specifications.
For manufacturers producing multiple sizes in small or medium batches, a direct square forming tube mill can greatly improve production flexibility and reduce downtime.
Factories producing mainly square and rectangular tubes
Frequent production size changes
Multiple specifications with small or medium batch sizes
Large square/rectangular structural tubes
Manufacturers seeking to reduce roll inventory
Factories where changeover downtime is a major cost
Producers expanding their square/rectangular tube product range
If your factory mainly produces a limited number of specifications continuously for long production runs, Great Wall engineers can also compare DFT with conventional round-to-square forming before recommending the line.
Step 1: Select target tube size
Step 2: Adjust forming roll positions
Step 3: Adjust sizing section
Step 4: Load preset parameters
Step 5: Trial production and dimensional check
Step 6: Start continuous production
A direct square forming tube mill is designed not only for flexible size production, but also for stable finished tube quality. Through controlled multi-point forming, welding, sizing and straightening, the line helps maintain consistent dimensions and surface quality throughout continuous production.
Key quality characteristics include:
Consistent Corner Radius: Controlled forming helps maintain uniform corner geometry and reduces excessive deformation at the tube corners.
Accurate Tube Dimensions: The sizing section controls tube width, height and diagonal dimensions to meet production requirements.
Good Side Flatness: Proper roll adjustment helps reduce concave or convex deformation on the flat sides of square and rectangular tubes.
Stable Wall Thickness: Optimized forming reduces unnecessary material stretching and helps maintain more consistent wall thickness, especially around the corners.
Reliable Weld Seam: Stable strip guiding and HF welding contribute to continuous weld quality and reliable tube strength.
Good Straightness: Final sizing and straightening help control longitudinal bending and twisting of finished tubes.
Clean Cut Quality: Flying saw or cold-cutting systems can provide accurate tube lengths and cleaner cut ends for downstream processing.
Depending on the tube specification and project requirements, the production line can be equipped with dimensional inspection, weld seam inspection, eddy current testing or ultrasonic testing.
Important inspection items generally include:
| Inspection Item | Quality Focus |
|---|---|
| Width & Height | Dimensional consistency |
| Diagonal Difference | Square and rectangular accuracy |
| Corner Radius | Uniform corner forming |
| Wall Thickness | Thickness variation control |
| Straightness | Tube bending and twisting |
| Weld Seam | Welding continuity and defects |
| Cut Length | Finished tube length accuracy |
Stable finished tube quality is particularly important for steel structures, machinery frames, solar mounting systems, automotive components and other applications where dimensional consistency affects assembly and downstream fabrication.
A DFT tube mill forms square and rectangular steel tubes directly from steel strip without first making round pipes. Compared with traditional methods, it offers better corner accuracy, lower roller costs, and faster changeover.
A direct square tube mill forms square tubes directly, while traditional methods first produce round tubes and then reshape them. A square tube forming machine improves efficiency, precision, and tooling flexibility.
A square tube making machine can produce square and rectangular steel tubes for construction, automotive, furniture, solar structures, and industrial applications.
Our square tube mill is suitable for carbon steel, galvanized steel, mild steel, hot-rolled steel, and cold-rolled steel strips.
Yes. One square pipe making machine can produce different tube sizes through roller adjustment or tooling replacement, improving production flexibility.
A square tube forming machine offers high precision, lower roller investment, stable welding quality, faster size changes, and improved production efficiency.
Yes. We provide installation, commissioning, operator training, and after-sales support for every square tube mill.
Yes. Our direct square tube mill can be customized according to tube size, material, factory layout, and production capacity requirements.
