ASTM 440C Stainless Steel Pipe
We offer this product and related grades with 100% factory direct pricing and free quotes available within 24 hours.
APPLICATION SCENARIOS
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440C is a martensitic, high-carbon chromium alloy offering the highest hardness (HRC 58-60) among commercial stainless steels. Unlike corrosion-focused austenitic grades, 440C prioritizes:
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Exceptional wear resistance (superior to D2 tool steel)
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High compressive strength (for bearing surfaces)
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Retained edge sharpness (critical for cutting systems)
Our pipes meet ASTM A511, AMS 5630, and ISO 683-17 standards for precision seamless tubing.
Why Choose Luokaiwei’s 440C Pipes?
| Advantage | Technical Benefit | Industry Impact |
|---|---|---|
| Max Hardness (HRC 60) | Triple the hardness of 304 stainless | 5X longer service life in wear applications |
| Fatigue Resistance | Compressive strength: 2,600 MPa | Ideal for high-load bearings/valves |
| Corrosion Resilience | 16-18% Cr content resists water/chemical exposure | Outperforms carbon tool steels |
| Precision Tolerances | OD ±0.05mm, wall ±5% (grinding finish available) | Eliminates post-machining costs |
| Heat Treatment Control | Proprietary cryogenic tempering (-73°C) | Eliminates retained austenite |
Technical Specifications
Table 1: Chemical Composition (Weight %)
| Element | 440C (S44004) | 420 (S42000) | 304 (S30400) |
|---|---|---|---|
| Carbon (C) | 0.95–1.20 | 0.15 min | ≤0.08 |
| Chromium (Cr) | 16.0–18.0 | 12.0–14.0 | 18.0–20.0 |
| Molybdenum (Mo) | 0.40–0.65 | – | – |
| Manganese (Mn) | ≤1.00 | ≤1.00 | ≤2.00 |
Table 2: Mechanical Properties (Hardened & Tempered)
| Property | 440C | 420 | Tool Steel D2 |
|---|---|---|---|
| Hardness (HRC) | 58–60 | 50–54 | 58–62 |
| Tensile Strength (MPa) | 1,960 | 1,600 | 2,050 |
| Yield Strength (MPa) | 1,825 | 1,350 | 1,900 |
| Impact Toughness (J) | 8 | 15 | 5 |
Critical Applications
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Aerospace:
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Aircraft bearing sleeves & hydraulic actuator rods
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Missile guidance system components
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Industrial Machinery:
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Plastic injection molding cores/ejector pins
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Textile spindle shafts
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Medical Devices:
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Surgical drill sleeves & biopsy needles (passivated)
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Automotive:
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Fuel injection nozzles & valve components
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Tooling:
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Cutting die bushings & precision gauges
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Luokaiwei’s Manufacturing Process
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Material Sourcing: Vacuum-induction melted (VIM) billets (O₂ ≤ 50 ppm)
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Pipe Formation:
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Seamless: Cold-drawn with mandrel (OD: 2–120 mm, wall: 0.5–10 mm)
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Surface Finish: Peeled (Ra 0.8 μm) or centerless ground (Ra 0.4 μm)
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Heat Treatment:
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Step 1: Austenitizing at 1,010–1,065°C (oil quench)
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Step 2: Deep cryogenic treatment at -73°C (stabilizes microstructure)
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Step 3: Triple tempering at 150–315°C (optimizes toughness)
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Quality Control:
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100% hardness mapping (Rockwell C)
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Eddy current testing for defects
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Salt spray testing per ASTM B117 (72h min)
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Design & Fabrication Guidelines
⚠️ Critical Considerations:
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Avoid Welding: Post-weld cracking risk due to high carbon content
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Stress Relief: Anneal at 760°C before machining complex shapes
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Corrosion Limits: Not for marine/chemical exposure – use 316L or duplex
✅ Best Practices:
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Machining:
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Carbide tools with TiAlN coating
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Low speeds (30–50 SFM), high feed rates
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Coolant mandatory to prevent work hardening
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Grinding:
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Use aluminum oxide wheels (46–60 grit)
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Avoid overheating (>150°C causes tempering)
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5 Essential FAQs
Q1: Can 440C pipes be used in food processing equipment?
A: No. High carbon content prevents effective passivation. Use 316L/904L for FDA compliance.
Q2: What is the maximum operating temperature?
A: 425°C (800°F) for short-term exposure. Prolonged use >315°C (600°F) causes temper softening.
Q3: Do you provide stress-relieved pipes for machining?
A: Yes. We supply:
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Annealed Condition (HB 255 max) for easy machining
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Pre-Hardened (HRC 58-60) for direct installation
Q4: How does 440C compare to tungsten carbide?
| Parameter | 440C | Tungsten Carbide |
|---|---|---|
| Hardness | HRC 60 | HRA 90+ |
| Toughness | Higher impact strength | Brittle |
| Cost | $50–100/kg | $300–600/kg |
Q5: Can you manufacture thin-walled (<0.5mm) 440C tubing?
A: Yes – our precision cold-drawing technology achieves walls down to 0.2mm (OD ≥ 3mm). Minimum order: 500 meters.
Why Partner with Luokaiwei?
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Specialized Expertise: 40% of production dedicated to martensitic steels
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Advanced Testing:
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Metallographic lab (grain size, carbide distribution analysis)
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Rotary bending fatigue tester (10⁷ cycle validation)
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Custom Solutions:
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ID/OD grinding with ±0.005mm tolerance
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Laser marking for traceability
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Order Your Precision 440C Pipes Today!
✅ Certifications: EN 10204 3.1 Mill Certificates + RoHS Compliance
✅ Lead Time: 4–6 weeks (standard), expedited options available
✅ MOQ: 100 kg (custom sizes), 500 kg (standard sizes)
Contact Luokaiwei:
📧 sales@luokaiweipipe.com
📱 +86 18912200505
