Monel Seamless Pipe & Tube – ASTM B165 Monel 400 (UNS N04400)
ASC LLP, Mumbai, supplies Monel seamless pipe and tube in Monel 400 (UNS N04400 / W.Nr. 2.4360) to ASTM B165 / ASME SB165. Heat-exchanger and condenser tube is supplied to ASTM B163. NPS ⅛” to 8″ pipe in SCH 5S – 80S and tube from 6 mm OD are available, annealed or stress-relieved, with EN 10204 3.1 certificates. See our full Monel range.
Monel Seamless Pipe – Quick Facts
- Grade: Monel 400, UNS N04400, W.Nr. 2.4360
- Specifications: ASTM B165 (pipe & tube), ASTM B163 (heat-exchanger tube), general requirements ASTM B829
- Sizes: NPS ⅛” – 8″, SCH 5S – 80S; tube 6 – 114 mm OD
- Condition: annealed or stress-relieved
- Ends: plain, bevelled or threaded
- Certificate: EN 10204 3.1; 3.2 / third-party inspection on request
What is Monel Seamless Pipe?
Monel seamless pipe is made from Monel 400, a nickel–copper alloy with about 63–70% nickel and 28–34% copper. It is extruded or pierced from a solid billet and cold-drawn to size, so it has no weld seam. Monel 400 is best known for its resistance to seawater, brine, hydrofluoric acid and caustic alkalis, and for its toughness from cryogenic temperatures up to about 480 °C.
Where Monel Pipe Works – and Where It Doesn’t
- Excellent: flowing seawater and brine, hydrofluoric acid, caustic soda and other alkalis, neutral salts; resists chloride stress-corrosion cracking.
- With care: dilute, de-aerated sulphuric and hydrochloric acids.
- Avoid: nitric and other oxidising acids, ferric and cupric chlorides, and sulphur-bearing gases above about 370 °C.
- Stagnant seawater: pitting can occur under deposits – design out crevices and dead legs.
Seamless vs Welded Monel Pipe
- Seamless (ASTM B165): no weld seam, uniform wall and properties – preferred for high pressure, heat-exchanger tube and critical service.
- Welded (ASTM B725 pipe / B730 tube): formed from strip or plate and welded – more economical in larger diameters and thin walls. See Monel welded pipes.
Seamless Monel pipe is normally available up to NPS 8″. Larger sizes are usually supplied as welded pipe.
Monel Grades for Pipe & Tube
Monel 400 Seamless Pipe (ASTM B165)
The standard grade for seamless pipe and tube – seawater, HF acid, caustic and heat-exchanger service. Full grade details: Monel 400 pipes.
Monel K-500 Pipe
Monel K-500 (N05500) is an age-hardenable grade made mainly as bar (ASTM B865) for shafts and bolting. ASTM B165 does not cover K-500; K-500 tube is supplied only by agreement. See Monel K-500 pipes.
Monel Seamless Pipe Specifications
| Item | Details |
| Grade | Monel 400 – UNS N04400, W.Nr. 2.4360 |
| Pipe & tube standard | ASTM B165 / ASME SB165 |
| Heat-exchanger & condenser tube | ASTM B163 / ASME SB163 |
| General requirements | ASTM B829 |
| Pipe sizes | NPS ⅛” – 8″ (10.3 – 219.1 mm OD) |
| Schedules | SCH 5S, 10S, 40S, 80S (ASME B36.19) |
| Tube sizes | 6 – 114 mm OD, metric or inch walls |
| Length | Single random, double random or cut length |
| Condition | Annealed or stress-relieved |
| Ends | Plain, bevelled or threaded |
| Testing | Chemical, tensile, flattening / flaring, hydrostatic or eddy-current; PMI and UT on request |
Types of Monel Pipe & Tube We Supply
| Product | Standard | Typical use |
| Seamless pipe | ASTM B165 | Seawater, chemical and caustic process lines |
| Seamless tube | ASTM B165 | Instrumentation and hydraulic lines |
| Heat-exchanger & condenser tube | ASTM B163 | Feed-water heaters, condensers, brine heaters |
| U-bend tube | ASTM B163 | Shell-and-tube heat exchangers |
| Welded pipe & tube | ASTM B725 / B730 | Monel welded pipes |
Monel Pipe Dimensions & Weight Chart (ASME B36.19)
| NPS | OD (mm) | SCH 5S (mm / kg/m) | SCH 10S (mm / kg/m) | SCH 40S (mm / kg/m) | SCH 80S (mm / kg/m) |
| ½” | 21.34 | 1.65 / 0.90 | 2.11 / 1.12 | 2.77 / 1.42 | 3.73 / 1.82 |
| ¾” | 26.67 | 1.65 / 1.14 | 2.11 / 1.43 | 2.87 / 1.89 | 3.91 / 2.46 |
| 1″ | 33.40 | 1.65 / 1.45 | 2.77 / 2.35 | 3.38 / 2.81 | 4.55 / 3.63 |
| 1¼” | 42.16 | 1.65 / 1.85 | 2.77 / 3.02 | 3.56 / 3.80 | 4.85 / 5.00 |
| 1½” | 48.26 | 1.65 / 2.13 | 2.77 / 3.48 | 3.68 / 4.54 | 5.08 / 6.06 |
| 2″ | 60.33 | 1.65 / 2.68 | 2.77 / 4.41 | 3.91 / 6.10 | 5.54 / 8.39 |
| 2½” | 73.03 | 2.11 / 4.14 | 3.05 / 5.90 | 5.16 / 9.68 | 7.01 / 12.79 |
| 3″ | 88.90 | 2.11 / 5.06 | 3.05 / 7.24 | 5.49 / 12.66 | 7.62 / 17.12 |
| 4″ | 114.30 | 2.11 / 6.54 | 3.05 / 9.38 | 6.02 / 18.02 | 8.56 / 25.02 |
| 6″ | 168.28 | 2.77 / 12.67 | 3.40 / 15.50 | 7.11 / 31.68 | 10.97 / 47.71 |
| 8″ | 219.08 | 2.77 / 16.56 | 3.76 / 22.38 | 8.18 / 47.69 | 12.70 / 72.46 |
Wall thickness per ASME B36.19; weights calculated for Monel 400 at a density of 8.80 g/cm³.
Chemical Composition of Monel 400 Pipe (ASTM B165)
| Element | Monel 400 (wt %) |
| Nickel (Ni) incl. cobalt | 63.0 min |
| Copper (Cu) | 28.0 – 34.0 |
| Iron (Fe) | 2.5 max |
| Manganese (Mn) | 2.0 max |
| Carbon (C) | 0.3 max |
| Silicon (Si) | 0.5 max |
| Sulphur (S) | 0.024 max |
Mechanical Properties of Monel Seamless Pipe
| Condition (ASTM B165) | Tensile strength (min) | 0.2% yield strength (min) | Elongation (min) |
| Annealed | 483 MPa (70 ksi) | 193 MPa (28 ksi) | 35% |
| Stress-relieved | 586 MPa (85 ksi) | 379 MPa (55 ksi) | 15% |
Minimum values per ASTM B165. Physical properties of Monel 400: density 8.80 g/cm³, melting range 1,300 – 1,350 °C, modulus ≈ 179 GPa.
Applications of Monel Seamless Pipes
| Industry | Typical Monel seamless pipe uses |
| Marine & shipbuilding | Seawater cooling and fire-main lines, ballast systems |
| Oil & gas / offshore | Seawater lift and injection lines, instrument tubing |
| Chemical processing | HF alkylation units, caustic soda evaporators, brine lines |
| Power & desalination | Feed-water heaters, condensers, brine heaters, heat exchangers |
| Hydrocarbon processing | Crude-column overhead condensers and process piping |
Related Monel Pages
- Monel 400 pipes and Monel K-500 pipes
- Monel welded pipes (ASTM B725 / B730)
- Monel fittings – including ASTM B366 Monel 400 fittings
- Monel flanges – including ASTM B564 Monel 400 flanges
- Monel plates, Monel round bar and Monel fasteners
- All Monel products
Why Choose ASC LLP for Monel Seamless Pipe?
- Correct specification: Monel 400 pipe and tube certified to ASTM B165 / B163 – annealed or stress-relieved as ordered.
- Full traceability: EN 10204 3.1 certificates with heat number, chemistry and tensile results; PMI and third-party inspection on request.
- Matched packages: pipe, fittings, flanges and fasteners in the same grade.
- Cut lengths and small quantities, plus export packing.
Send NPS or OD × wall, schedule, length and quantity to sales@amardeepsteel.com or call 022-67439130.
Frequently Asked Questions – Monel Seamless Pipe
Which ASTM standard covers Monel seamless pipe?
ASTM B165 (ASME SB165) covers seamless pipe and tube in Monel 400, UNS N04400. Heat-exchanger and condenser tubes are supplied to ASTM B163, and welded Monel pipe and tube to ASTM B725 and B730.
What are the mechanical properties of ASTM B165 Monel 400 pipe?
Annealed pipe has minimums of 483 MPa (70 ksi) tensile, 193 MPa (28 ksi) yield and 35% elongation. Stress-relieved pipe has minimums of 586 MPa (85 ksi), 379 MPa (55 ksi) and 15%.
What sizes of Monel seamless pipe are available?
Monel seamless pipe is commonly available from NPS ⅛” to 8″ in schedules 5S, 10S, 40S and 80S, and as tube from about 6 to 114 mm OD. Larger sizes are normally supplied as welded pipe.
Is Monel K-500 available as seamless pipe?
ASTM B165 covers only Monel 400. Monel K-500 is made mainly as bar to ASTM B865; K-500 tube can be supplied by agreement for special applications.
Is Monel pipe suitable for seawater?
Yes. Monel 400 resists flowing seawater and brine very well and does not suffer chloride stress-corrosion cracking. In stagnant seawater it can pit under deposits, so dead legs and crevices should be avoided.
What is the difference between Monel seamless and welded pipe?
Seamless pipe (ASTM B165) has no weld seam and is preferred for high-pressure and heat-exchanger service. Welded pipe (ASTM B725) is formed from strip or plate and is more economical in larger diameters.
Oil & Gas / Offshore
Marine & Shipbuilding
Chemical Processing
Power & Desalination
Global Reach
ASC LLP supplies Monel and other nickel-alloy piping to customers in the USA, Europe, the Middle East and Asia, including Japan, with secure packing and full documentation. Buyers worldwide rely on our Monel seamless pipes for certified material and traceability.
Countries We Export To
UNITED STATES, EUROPE, UK, UAE, SAUDI ARABIA, OMAN, KUWAIT, JORDAN, QATAR, INDONESIA, MALAYSIA, BRAZIL, SPAIN, ITALY, FRANCE, GERMANY, BAHRAIN, SRI LANKA, AZERBAIJAN, AUSTRALIA, AUSTRIA, PHILIPPINES, TURKEY, RUSSIA, IRAN, IRAQ, CANADA, KOREA, JAPAN, YEMEN, FINLAND, ZIMBABWE, HUNGARY, PORTUGAL, VIETNAM, MOROCCO, THAILAND, SOUTH AFRICA, MEXICO, SINGAPORE, GREECE, KUWAIT, POLAND, NEW ZEALAND, SWEDEN, SWITZERLAND, BELGIUM, BHUTAN, BANGLADESH, TAIWAN, ROMANIA, CAMBODIA, KAZAKHSTAN, AFGHANISTAN.
