Monel K500 Seamless Tube

UNS N05500 | 2.4375 | ASTM B165

Monel K500 Seamless Tube (N05500 / 2.4375) is manufactured to ASTM B165 from tube billet, cold-drawn to the required outside diameter and wall thickness. Supplied from our Wenzhou mill with EN 10204 3.1 mill test certificate, PMI and dimensional inspection on request.

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What Is a Seamless Monel K500 Tube?

Monel K500 (UNS N05500) is a precipitation-hardenable nickel-copper alloy made by adding small amounts of aluminium and titanium to the Monel 400 composition. Age hardening roughly doubles the yield strength and hardness of Monel 400 while retaining the same excellent corrosion resistance in seawater, hydrofluoric acid and alkaline media — which makes K500 tubing ideal for pump shafts, valve trim and subsea hardware.

Seamless Monel K500 Tube (UNS N05500) is a high-performance nickel-copper alloy tube designed for applications requiring exceptional strength, corrosion resistance, and reliability under extreme conditions.

Monel K500 is an age-hardenable alloy derived from Monel 400. Through the controlled addition of aluminum (Al) and titanium (Ti), and a precipitation hardening process, the alloy forms sub-microscopic Ni₃(Al, Ti) phases within the matrix.

The seamless production process ensures:

Monel K500 Key Features and Technical Advantages

Feature	Description
Exceptional Strength and Hardness	Age hardening roughly doubles the yield strength and hardness of Monel 400 while retaining useful ductility, allowing K500 tubing to carry high mechanical loads.
Outstanding Corrosion Resistance	Monel K500 resists seawater, hydrofluoric acid, sulphuric acid and alkaline media, and is essentially immune to chloride stress-corrosion cracking.
Wide Temperature Performance	The alloy retains its mechanical properties from cryogenic temperatures up to about 480 °C, covering both LNG and hot-process duty.
Non-Magnetic and Spark-Resistant	The alloy stays non-magnetic after age hardening and resists sparking, which suits it to instrumentation and hazardous-area hardware.
Seamless Structural Integrity	Seamless construction removes the weld seam, giving a homogeneous structure with no weak zone along the tube length.

Monel K500 Product Specifications and Data

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	≤0.2	≤1.5	≤0.010	≤0.5	≥63.0	27.0-33.0	0.5-2.0	0.35-0.85	2.30-3.15

Seamless Monel K500 Tube is specifically designed to maintain its high strength and shape in high-stress applications.

Tensile Strength	Yield Strength	Elongation	Hardness
≥ 1100 MPa	≥ 758 MPa	≥ 20%	26-32 HRC

These physical properties highlight the material's ability to perform reliably under a wide range of conditions.

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 x 10⁻⁶ Ω·m (20°C)

Nominal Outside Diameter, in. (mm)	Outside Diameter in. (mm)		Thickness of Specified Nominal Wall , %		Thickness of Specified Minimum Wall , %
Nominal Outside Diameter, in. (mm)	Plus	Minus	Plus	Minus	Plus	Minus
Over 0.400 (10) to 5/8 (16), excl	0.005 (0.13)	0.005 (0.13)	15	15	30	0
5/8 (16) to 1 1/2 (38), incl	0.0075 (0.19)	0.0075 (0.19)	10	10	22	0
Over 1 1/2 (38) to 3 (76), incl	0.010 (0.25)	0.010 (0.25)	10	10	22	0
Over 3 (76) to 4 1/2 (114), incl	0.015 (0.38)	0.015 (0.38)	10	10	22	0
Over 4 1/2 (114) to 6 (152), incl	0.020 (0.51)	0.020 (0.51)	12.5	12.5	28	0
Over 6 (152) to 6 5/8 (168), incl	0.025 (0.64)	0.025 (0.64)	12.5	12.5	28	0
Over 6 5/8 (168) to 8 5/8 (219), incl	0.031 (0.79)	0.031 (0.79)	12.5	12.5	28	0

Monel K500 Dimensional Standards and Tolerances

Monel K500 seamless tubes are supplied to the dimensional tolerances of ASTM B163 / B829 unless a tighter project specification applies.

Monel K500 Common Industrial Applications

Industry	Typical Applications
Marine and Offshore Engineering	Pump shafts and valve trim Subsea hardware components Seawater handling systems
Oil and Gas Industry	Downhole instrumentation housings Drill-collar and logging tools High-strength process tubing
Chemical and Petrochemical Processing	Pump and agitator shafts Valve and impeller components Hydrofluoric acid service parts
Aerospace and Instrumentation	Non-magnetic instrument components Spark-resistant hardware Precision mechanical parts

Monel K500 Quality Assurance and Production Process

Process Step	Description
Certification	All Monel K500 tubes are supplied to ASTM B163 / ASME SB163 and ASTM B829 with EN 10204 3.1 mill test certificates. Third-party inspection (SGS, BV, TUV, Lloyd's), PMI reports and full heat-number traceability can be provided on request.
Non-Destructive Testing (NDT)	Hydrostatic or eddy-current testing is performed on 100% of tubes. Ultrasonic testing (UT) and dye-penetrant inspection (PT) are available for critical service, with records retained for each production lot.
Material Verification	Positive Material Identification (PMI) and spectrometric analysis confirm that the chemical composition matches the ordered grade. Intergranular corrosion (IGC) testing to ASTM A262 Practice E is available for austenitic and nickel-alloy tubes.
Mechanical Testing	Tensile, yield, elongation and hardness tests are carried out per heat. Flattening, flaring and reverse-bend tests verify ductility, while creep-rupture data can be supplied for high-temperature grades.
Dimensional Inspection	Outside diameter, wall thickness, ovality and straightness are measured against ASTM A1016 / A1016M or EN 10216-5 tolerances. Length, square-cut ends and end-finish conditions are verified before packing.

Monel K500 vs Monel 400 / Inconel 625 – Technical Comparison

Monel K500 is the precipitation-hardened version of Monel 400. Comparing it with Monel 400 and Inconel 625 clarifies where strength rather than corrosion resistance is the design driver.

Strengthening Mechanism

Monel K500: age hardened with aluminium and titanium — roughly double the yield strength of Monel 400
Monel 400: solid-solution nickel-copper alloy, no hardening treatment
Inconel 625: nickel-chromium-molybdenum alloy with a different corrosion envelope entirely

Corrosion Resistance

K500 retains the seawater, hydrofluoric acid and alkaline resistance of Monel 400. Inconel 625 is the better choice for chloride-induced pitting and crevice attack and for high-temperature oxidation, but it does not offer the same performance in hydrofluoric acid.

Magnetic Properties

Both Monel grades remain essentially non-magnetic, and K500 stays non-magnetic after ageing — a decisive advantage for instrumentation and sensor housings.

Selection Guide

Choose Monel K500 where high strength, hardness or wear resistance is needed in a marine or hydrofluoric acid environment
Choose Monel 400 where corrosion resistance alone governs and higher strength is unnecessary
Choose Inconel 625 for chloride pitting service and high-temperature oxidation

Frequently Asked Questions About Monel K500 Seamless Tubes

What is Monel K500 seamless tube?

Monel K500 (UNS N05500) is a precipitation-hardenable nickel-copper alloy tube made by adding aluminium and titanium to the Monel 400 composition and age hardening it. It offers roughly double the yield strength of Monel 400.

What is the difference between Monel 400 and Monel K500?

Both share the nickel-copper base and the same seawater, hydrofluoric acid and alkaline corrosion resistance. K500 is age hardened, which roughly doubles its yield strength and hardness, at the cost of being more complex to weld and fabricate.

What standard covers Monel K500 tube?

Monel K500 seamless tube is supplied to ASTM B163 / ASME SB163, with ASTM B829 covering general requirements. Mechanical property requirements follow the annealed and aged condition specified by the purchaser.

What is Monel K500 tube used for?

Monel K500 is used for pump shafts and valve trim, subsea and offshore hardware, downhole instrumentation housings, and non-magnetic or spark-resistant components in marine and chemical service.

Request a Monel K500 Tube Quotation

Send your Seamless Monel K500 Tube enquiry with grade, application, size (OD and wall thickness or schedule), quantity, length, end finish and inspection requirements. Our technical team will confirm availability, testing scope and lead time.

Request a Monel K500 Tube Quotation