Integrated In-Line Straightening After Cold Drawing – One Continuous Process to ≤0.3mm/m Straightness
No secondary straightening pass required. Material exits the line ready for automotive and structural assemblies – saving time, reducing handling, and improving overall efficiency.
The Traditional Problem: Drawing and Straightening as Separate Steps
For decades, cold drawing and straightening have been treated as two distinct operations. A tube or bar is drawn on one machine, then transported – often manually – to a separate straightening machine. This fragmented workflow introduces:
Extra handling – increased risk of surface damage, scratches, and dents
Additional floor space – two machines, two operators, and intermediate storage
Longer lead times – material waits between processes
Inconsistent quality – each machine operates independently, with no shared feedback
Higher labor costs – dedicated operators for each station
For automotive and structural applications, where straightness directly affects assembly fit, weld quality, and fatigue performance, these inefficiencies are no longer acceptable.
The FangRong Solution: Integrated In-Line Straightening
FangRong’s integrated cold drawing line combines the drawbench and a precision straightening machine into one continuous process. As the tube or bar exits the drawing die, it is automatically fed into an in-line multi-roll straightener – without manual intervention, intermediate storage, or a second setup.
The result: straightness ≤0.3 mm/m in a single pass. No secondary straightening required. Material exits the line ready for automotive and structural assemblies.
How the Integrated Process Works
Step | Action | Technology |
1. Pointing | Tube/bar end is reduced for die entry | Hydraulic or rotary pointer |
2. Cold drawing | Material is pulled through the die – reduced to final dimensions | Hydraulic or servo-hydraulic drawbench |
3. In-line straightening | Drawn material passes directly into a multi-roll straightener | Staggered rolls correct camber and twist |
4. Laser verification | Real-time straightness measurement | Closed-loop feedback – auto-adjusts if needed |
5. Exit | Straightened material is stacked or cut to length | Ready for assembly – no secondary pass |
All steps are synchronized by a single PLC – one operator supervises the entire line.
Key Technical Specifications – Integrated Drawing & Straightening Line
Parameter | Range |
Tube OD | 6 – 200 mm |
Bar diameter | 5 – 150 mm |
Wall thickness (tubes) | 0.5 – 20 mm |
Drawing force | 10 – 500 tons |
Straightness achieved | ≤0.3 mm/m (typical ≤0.2 mm/m) |
Drawing speed | 0 – 20 m/min |
Straightening speed | Synchronized with drawing speed |
Control system | PLC with touchscreen, recipe storage |
Why In-Line Straightening Outperforms Separate Operations
Factor | Separate Drawing + Straightening | Integrated In-Line System |
Handling steps | Multiple – load, unload, transfer, reload | Zero – continuous flow |
Surface damage risk | High – manual handling | Negligible – guided transfer |
Straightness consistency | Variable – two separate setups | Consistent – closed-loop control |
Floor space | Two machines + storage | One compact line |
Labor requirement | 2–3 operators | 1 operator |
Cycle time | Longer – waiting between processes | Continuous – no waiting |
Secondary straightening | Often required | Not required |
Traceability | Fragmented logs | Single batch record |
Materials & Applications
Material | Typical Products | Why In-Line Straightening Matters |
Carbon steel | Hydraulic cylinder tubes, drive shafts, structural tubes | Straightness ensures proper fit in welded and bolted assemblies |
Stainless steel | Automotive fuel lines, medical tubing, food processing tubes | No surface damage – passive layer preserved |
Aluminum | EV battery cooling tubes, structural profiles | Soft material – no handling scratches |
Copper & brass | HVAC coils, busbars, valve stems | Leak-free joints – precise straightness for brazing |
Industries served: automotive, EV, aerospace, hydraulics, construction, energy, and general engineering.
Real-World Example – Automotive Structural Tubes
A manufacturer of structural steel tubes for automotive chassis applications previously drew tubes on one machine and straightened them on a separate machine. The process required two operators, intermediate storage, and a secondary straightening pass that added 25 minutes per batch.
After installing a FangRong integrated drawing and in-line straightening line:
Metric | Before (Separate) | After (Integrated) |
Operators | 2 per shift | 1 per shift |
Straightness | 0.5 mm/m after drawing; 0.25 mm/m after secondary straightening | ≤0.25 mm/m in one pass |
Secondary straightening | Required | Eliminated |
Cycle time per batch | 45 minutes | 18 minutes |
Surface damage | 2.5% scrap | <0.3% |
Floor space | 35 m² | 18 m² |
Payback period: 12 months.
Why Choose FangRong for Integrated Drawing & Straightening?
26 years of cold drawing and straightening experience – thousands of integrated lines installed worldwide
Custom engineering – line configured to your tube/bar dimensions, material, and production targets
Closed-loop precision – ≤0.3 mm/m straightness guaranteed, often ≤0.2 mm/m
Single-source accountability – one supplier for pointing, drawing, straightening, and cutting
Global service network – installation, training, remote diagnostics, spare parts
Conclusion – One Continuous Process, Zero Secondary Straightening
For manufacturers of automotive and structural tubes and bars, the integrated in-line straightening system eliminates the inefficiencies of separate operations. By combining drawing and straightening into one continuous process, FangRong delivers ≤0.3 mm/m straightness in a single pass – saving time, reducing handling, and improving overall efficiency. Material exits the line ready for assembly, with no secondary straightening required.
FangRong provides complete machine and solution services for cold drawing, straightening, and pointing – all customized to your specifications.
Contact us to discuss your integrated line requirements.
Know More About Us FangRong Metallurgical Equipment Manufacturer in China since 1998. Professional in Metal Straightening machine, Cold Drawing machine, Push Pointer Drawing Machine, Automatic Three Lines Drawing Machine, Thread rolling machine, Tube-end shrinking machine, Pointing Machine, Core pipe machine, Polishing Machine etc.
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Keywords: Integrated in-line straightening, cold drawing and straightening line, ≤0.3mm/m straightness, one continuous process, no secondary straightening, automotive tube drawing, structural tube straightening, FangRong integrated line.
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