What Is Monel K500 Seamless Pipe?
Seamless Monel K500 Pipe (UNS N05500) is a high-performance nickel-copper alloy pipe known for its exceptional strength, corrosion resistance, and reliability in extreme environments. Unlike Monel 400, Monel K500 is an age-hardenable alloy. Through the addition of controlled amounts of aluminum (Al) and titanium (Ti), the material can undergo precipitation hardening, significantly increasing its mechanical strength.
The seamless manufacturing process (hot piercing and cold drawing) ensures no weld seams, a uniform grain structure, and superior performance under high pressure and cyclic stress.
Key Features and Advantages
Monel K500 seamless pipes offer a unique combination of benefits that make them invaluable in demanding applications:
High Strength & Hardness: Yield strength up to 3× higher than Monel 400, with excellent performance in high-pressure systems and high-torque mechanical applications.
Outstanding Corrosion Resistance: Excellent resistance to seawater and brackish water, hydrofluoric acid (HF), and sulfuric acid (H₂SO₄), making the alloy suitable for aggressive marine and chemical environments.
Non-Magnetic Performance: Remains non-magnetic even at -101°C (-150°F), ideal for downhole tools and electronic and measurement equipment.
Excellent Dimensional Stability: Maintains mechanical integrity under thermal cycling and mechanical stress.
Spark Resistance: Intrinsically safe for explosive environments, gas and petrochemical plants.
Product Specifications and Data
To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for Monel K500.
Equivalent Grade
| UNS | Common grade name | EN material number | EN steel name | JIS grade | GB/T grade |
|---|---|---|---|---|---|
| N05500 | Monel K-500 | 2.4375 | NiCu30Al3Ti | – | NS6500 / Ni68Cu28Al (legacy) |
Grade correspondence does not make ASTM, ASME, EN, JIS and GB delivery requirements interchangeable. Confirm chemistry, heat treatment, mechanical properties, dimensions, testing and certification against the purchase specification. See the grade designation index.
Chemical Composition
The composition of Monel K500 is carefully balanced to achieve its superior strength and corrosion resistance.
| Grade | C | Mn | S | Si | Ni | Cu | Fe | Ti | Al |
|---|---|---|---|---|---|---|---|---|---|
| Monel 400 | ≤0.3 | ≤2.0 | ≤0.024 | ≤0.5 | ≥63.0 | 28.0-34.0 | ≤2.5 | – | – |
| Monel K-500 | ≤0.25 | ≤1.5 | ≤0.010 | ≤0.5 | ≥63.0 | 27.0-33.0 | ≤2.0 | 0.35-0.85 | 2.30-3.15 |
Typical Mechanical Properties
Monel K500 is specifically designed to maintain its strength and shape in high-stress, corrosive environments.
| Tensile Strength | Yield Strength | Elongation | Hardness |
|---|---|---|---|
| ≥ 965 MPa | ≥ 690 MPa | ≥ 20% | 27-35 HRC |
ASTM B865 minimums (hot-finished and age-hardened): tensile 965 MPa (140 ksi) min, yield 690 MPa (100 ksi) min, elongation 20% min. No ASTM seamless pipe specification names UNS N05500; chemistry and aged acceptance values are taken from ASTM B865, with general requirements per ASTM B829.
Typical Physical Properties
These physical properties highlight the material’s ability to perform reliably across a range of environments.
| Density | Melting Point | Thermal Expansion | Thermal Conductivity | Modulus of Elasticity | Electrical Resistivity |
|---|---|---|---|---|---|
| 8.44 g/cm³ | 1315 – 1350 °C | 13.7 μm/m·°C (20-100°C) | 17.5 W/m·K (20°C) | 179 GPa | 0.62 × 10⁻⁶ Ω·m (20°C) |
Size Tolerance Chart (mm)
| Specified/Calculated Nominal OD (Inches) | Permissible Variation (Inches) | Specified/Calculated Nominal OD (mm) | Permissible Variation (mm) |
|---|---|---|---|
| 0.500 to 5⁄8, excl. | ±0.005 | 12.7 to 15.8, excl. | ±0.127 |
| 5⁄8 to 1 1⁄2, incl. | ±0.0075 | 15.8 to 38.1, incl. | ±0.190 |
| Over 1 1⁄2 to 3 1⁄2, incl. | ±0.010 | Over 38.1 to 88.9, incl. | ±0.254 |
| Over 3 1⁄2 to 4 1⁄2, incl. | ±0.015 | Over 88.9 to 114.3, incl. | ±0.381 |
| Over 4 1⁄2 to 6, incl. | ±0.020 | Over 114.3 to 152.4, incl. | ±0.508 |
| Over 6 to 6 5⁄8, incl. | ±0.025 | Over 152.4 to 168.3, incl. | ±0.635 |
| Specified/Calculated Nominal OD (Inches) | Permissible Variation (Inches) | Specified/Calculated Nominal OD (mm) | Permissible Variation (mm) |
|---|---|---|---|
| 2 1⁄2 to 5 1⁄2, excl. | ±0.031 | 63.5 to 139.7, excl. | ±0.787 |
| 5 1⁄2 to 9 1⁄4, incl. | ±0.047 | 139.7 to 234.9, incl. | ±1.19 |
| Condition | Specified/Calculated Nominal OD (Inches) | Permissible Variation (Wall Thickness) |
|---|---|---|
| Cold-Finished | 0.500 to 5⁄8, excl. | ±15.0% |
| 5⁄8 to 4 1⁄2, incl. | ±10.0% | |
| Over 4 1⁄2 to 6 5⁄8, incl. | ±12.5% | |
| Hot-Finished | 2 1⁄2 to 9 1⁄4, incl. | ±12.5% |
Common Industrial Applications
Monel K500 seamless pipes are widely used in demanding industries:
Marine & Subsea Engineering
- Pump shafts
- Seawater valves
- Mooring components
- Marine fasteners
Oil & Gas Industry
- Downhole tools
- Non-magnetic drill collars
- Valve trim in sour gas (H₂S) environments
Chemical Processing
- Handling hydrofluoric acid
- Acid transfer systems
- Pumps and valves
Aerospace Industry
- High-strength fasteners
- Engine components
Quality Assurance & Testing
To ensure reliability and compliance, each pipe undergoes strict quality control:
Material Certification
- EN 10204 3.1 / 3.2
PMI (Positive Material Identification)
- 100% verification
Non-Destructive Testing (NDT)
- Ultrasonic Testing (UT)
- Eddy Current Testing (ET)
- Hydrostatic Testing
Mechanical Testing
- Impact test
- Flattening & flaring test
Corrosion Testing
- Intergranular corrosion
- Pitting resistance evaluation
Why Choose Monel K500 Seamless Pipe?
- Exceptional strength and durability
- Superior corrosion resistance in marine environments
- Non-magnetic and spark-resistant properties
- Long service life with low maintenance cost
- Reliable performance in extreme conditions
Standards & Compliance
- ASTM B865 / ASME SB865
- ASTM B829 / ASME SB829
- EN 10204 (3.1 / 3.2 certification)
Send the NPS and schedule (or actual OD and wall), quantity, length, end finish and the inspection items you need as acceptance criteria — you will get a written quotation stating the specification and edition, delivery condition, documents included and lead time.
