Products Advantages
1. Superior Machinability & Formability
✔ Softened Structure (HRB 60-80) – Easier to cut, drill, and thread than cold-rolled pipes
✔ Excellent Ductility (Elongation 25-35%) – Resists cracking during bending/flaring
✔ Consistent Hardness (±5 HRB variation) – Predictable machining performance
2. Precision Surface Quality
✔ Scale-Free Finish – Smooth black oxide layer (Ra ≤3.2µm) for paint/powder coating adhesion
✔ Tight Tolerances – OD ±0.1mm, wall thickness ±10% (ideal for CNC machining)
✔ Burr-Free Ends – Laser-cut or cold-sawed for clean assembly
3. Cost-Effective Production
✔ Lower Energy Input vs. galvanizing – Annealing requires only controlled cooling
✔ Reduced Tool Wear – Softer material extends tool life by 20-30%
✔ Minimal Rejection Rate – Eddy current tested for 100% defect-free delivery
4. Thermal Process Benefits
✔ Stress-Relieved – Eliminates internal stresses from cold forming
✔ Uniform Microstructure – Enhanced mechanical properties throughout the pipe
✔ No Hydrogen Embrittlement – Unlike acid-pickled alternatives
Products Specifications
1. Standard Dimensions
| Parameter | Range |
|---|---|
| Outer Diameter | 6mm - 219mm (0.24" - 8.63") |
| Wall Thickness | 0.5mm - 12mm (SCH 10 - SCH 80) |
| Length | 5.8m/6m standard (Custom 1m-12m) |
| Tolerance | OD: ±0.1mm • WT: ±10% |
2. Material Properties
| Grade | Yield Strength | Tensile Strength | Elongation |
|---|---|---|---|
| ASTM A513 | 180-350 MPa | 300-500 MPa | 20-35% |
| EN 10305-1 | 220-320 MPa | 350-480 MPa | 22-30% |
| JIS G3441 | 195-245 MPa | 330-490 MPa | 25-35% |
Applications
1. Automotive & Machinery Manufacturing
✔ Hydraulic Cylinder Tubes: Smooth interior for piston movement
✔ Bearing Housings: Easy machining for precision components
✔ Gear Shafts: Excellent cold-forming characteristics
2. Furniture & Architectural Use
✔ Modern Furniture Frames: Clean black finish requires no painting
✔ Handrails & Decorative Elements: Uniform appearance with matte texture
✔ Lighting Structures: Easy to bend/weld for custom designs
3. Fluid Transfer Systems
✔ Low-Pressure Pneumatic Lines: Scale-free interior prevents contamination
✔ Lubrication Oil Pipes: Compatible with petroleum-based fluids
✔ HVAC Duct Connectors: Formable without cracking
4. Industrial Equipment
✔ Conveyor Rollers: Balanced hardness for wear resistance
✔ Textile Machinery Guides: Smooth surface reduces fiber friction
✔ Agricultural Implement Frames: Withstands moderate outdoor exposure (when oiled)
5. Electrical & Electronics
✔ Cable Management Conduits: Non-conductive oxide layer
✔ Equipment Mounting Posts: Machinable for screw threads
fAQ
Q1: Can black annealed pipes be welded?
A: Yes, but requires scale removal at weld zones for best results. Prefer TIG/MIG over stick welding.
Q2: What's the lifespan indoors?
A: 5-8 years with proper oiling (vs. 1-2 years for untreated black steel).
Q3: MOQ and lead time?
A: MOQ 3 tons (stock sizes), 10-20 days for custom orders.
Q4: How to prevent rust during storage?
A: Store in dry conditions with VCI paper or apply light oil monthly.
