Products Introduction

What is Monel 400? Moel 400 also called(UNS N04400,this i is a nickel-copper alloy containing approximately 67% nickel and 23% copper, with iron and manganese additions. This nickel copper alloy is a single-phase solid solution that can only be hardened by cold working. Monel 400 material delivers excellent resistance to seawater, hydrofluoric acid, sulfuric acid, hydrochloric acid, and alkalis. It is highly resistant to sea water and steam at high temperatures, as well as to salt and caustic solutions. and it is the preferred material for marine engineering, shipbuilding, chemical processing, oil and gas, heat exchangers, desalination equipment, and pump and valve components.

Monel 400 composition and physical strength

Monel 400 Chemical components(%)

Mechanical properties

Physical properties

Alloy 400 Monel Available Products and Standards

1. ASTM B127 is Standard Specification for Nickel-Copper Alloy Plate, Sheet, and Strip

Size Range:

• Monel 400 Sheet: 0.5 – 5.0 mm thick × up to 1000 mm wide.

• Monel 400 Plate: 5.0 – 180 mm thick × up to 3000 mm wide.

Sheet and Plate Surface treatment options: Annealed, Hot rolled, Cold rolled, Pickled, Bright as per customized request.

Factroy inner test and inspection : Chemical analysis, tensile test, hardness, magnetic permeability (optional), corrosion test (seawater, acid resistance), dimensional inspection

2. ASTM B164 is Standard Specification for Nickel-Copper Alloy Rod, Bar, and Wire

Products Size Range:

• Monel 400 Wire size range: 0.01 – 15.0 mm dia (coils or straight)

• Monel 400 Round bar size range: 8 – 355 mm dia (cold drawn or hot rolled

Goods Surface: Annealed, Cold drawn, Ground, Pickled, Bright

How can we control product quality ? we will inspect monel 400 Chemical composition, mechanical test (tensile, yield, elongation), eddy current test, dimensional inspection before goods take from our factroy.

3. ASTM B165 is Standard Specification for Nickel-Copper Alloy Seamless Pipe and Tube

As per ASTM B165,our supply Size Range:

• Monel 400 Pipe: 1/8″ – 12″ NPS (10.3 – 323.8 mm OD) × Schedule 5S, 10S, 40S, 80S for smaller size.

• Monel 400 Tube: 6 – 260 mm OD × 1 – 25 mm wall thickness for bigger size.

Monel tube, monel pipe Surface usually as per  Annealed, Pickled, Bright as for customer

Same as Monel 400 Round bar, We do all related test for our metal products which include Hydrostatic test, nondestructive electric test, flattening test, chemical and mechanical test, flaring test

Monel 400 Applications

1. Marine Engineering & Shipbuilding

• Monel 400 plate delivers exceptional resistance for seawater piping, propeller shafts, pump impellers, and shipboard cooling systems, This seawater resistant Monel alloy resists pitting, crevice corrosion, and biofouling in warm, high‑chloride marine environments. 

• About shipbuilding structural components and deck machinery, Alloy 400 monel flat washer and other custom monel 400 hex nuts withstand salt spray, tidal cycling, and marine growth. and this grade eliminates the need for coatings or cathodic protection in most marine services.

• Monel 400 pipe are specified for seawater intake systems, ballast water lines, and firewater mains on ships and offshore platforms.

2. Chemical Processing & Hydrofluoric Acid Service

• For chemical processing hydrofluoric acid (HF) alkylation units, Monel 400 pipe is the standard material—no other commercially available alloy offers the same combination of HF resistance and mechanical strength at reasonable cost. This acid resistant Monel 400 grade handles all concentrations of HF up to boiling point.

• For sulfuric acid, hydrochloric acid, and alkalis handling, Alloy 400 tubing provides excellent anit -rust in reducing environments which is widely used in acid storage tanks, transfer lines, and reactor vessels.

• UNS N04400 bar are machined into pump shafts, valve stems, impellers, and fittings for chemical process equipment.

3. Oil & Gas / Offshore Equipment

• For wellhead equipment, downhole tubing, and topside process piping in sour gas service, Monel 400 for oil and gas resists sulfide stress cracking and chloride pitting.

• For offshore platforms and subsea manifolds, ASTM B127 Monel 400 plate provide reliable performance in splash zones and submerged conditions.

• Monel 400 flanges and fittings are specified for critical connections in oil production systems.

4. Heat Exchangers & Desalination Equipment

• For shell‑and‑tube heat exchangers, condensers, and reboiler bundles, Monel 400 tube offer high thermal conductivity and excellent resistance to localized attack in seawater and brine service.

• For MSF and RO desalination plants, Monel 400 for desalination equipment resists hot concentrated brine and scale formation in evaporator sections and brine heaters.

• UNS N04400 seamless tube maintains integrity under thermal cycling and corrosive fluids in power generation and chemical plants.

5. Pumps, Valves & General Industrial Equipment

• For pumps, valves, shafts, and fasteners requiring both strength and corrosion resistance, Monel 400 round bar offer moderate‑to‑high strength with excellent fabricability.

• Monel 400 forgings are used for high‑integrity components in demanding service conditions.

6. Power Generation & Petrochemical

• For power generation feedwater heaters and condenser tubing, Alloy 400 tube provides long‑term reliability in aggressive cooling water environments.

• For petrochemical processing equipment including heat exchangers and process piping, ASTM B165 Monel 400 pipe handles corrosive process streams with minimal maintenance.

FAQ – Monel 400 Alloy

Q: What is the difference between Monel 400 and Inconel 600?

A: Monel 400 alloy is a nickel-copper alloy (approx. 67% Ni, 23% Cu) optimized for room temperature marine applications—seawater resistance, hydrofluoric acid, and reducing environments. Inconel 600 is a nickel-chromium-iron alloy (approx. 72% Ni, 14–17% Cr) designed for high temperature applications—oxidation resistance up to 2000°F and caustic environments. alloy 400 Monel excels in seawater and acid handling; Inconel 600 is the choice for furnace and high‑temperature service.

Q: Is Monel 400 suitable for hydrofluoric acid service?

A: Yes. Monel 400 is one of the few alloys resistant to hydrofluoric acid (HF) across all concentrations. It is the standard material for HF alkylation unit piping, vessels, and equipment—no other commercially available alloy offers the same combination of HF resistance and mechanical strength at reasonable cost.

Q: Can Monel alloy 400 be welded without post‑weld heat treatment?

A: Yes. Monel 400 sheet can be welded using TIG, MIG, SMAW, and other standard processes. The nickel-copper alloy maintains its corrosion resistance in the as‑welded condition, and post‑weld heat treatment is generally not required for most applications. For optimal rust resistance, annealing may be performed if specified.

Q: What is the maximum operating temperature for Monel 400?

A: Monel 400 alloy operates effectively from cryogenic temperatures up to approximately 500°F (260°C) in continuous service. It is limited to approximately 480°C in air due to scaling. For continuous service above 500°F, Inconel 600 is recommended.

MONO Group specializes in the supply of Monel 400 and a complete range of nickel‑copper alloys for marine, chemical, and oil‑gas environments. As a Monel 400 supplier, Our offer produces include plates, sheets, round bar, seamless tubes, welded pipes,Monel 400 Springs, and other custom‑machined parts – the production standard as per ASTM Standard to meet most custmer needs. We also provide cut‑to‑size, precision machining, and surface finishing services to meet your exact needs. For detailed technical datasheets, current stock availability, or a competitive quotation, please contact us at info@monokj.com – our team is ready to respond quickly with professional advice.