Inconel 625 Seamless Pipes & Tubes – UNS N06625 Pipe Manufacturer & Supplier
Table of Content
- Introduction to Inconel 625 Superalloy
- Inconel 625 vs Other High-Temperature Alloys
- Alloy 625 Seamless Pipe vs Welded Pipe
- ASTM B444 & ASME SB444 Specifications
- Manufacturing Range & Dimensional Standards
- Various Types of Inconel 625 Pipes & Tubes
- Pipe Weight Chart (Common Sizes)
- Applications & Industries Served
- Quality Assurance & Testing
- Export Destinations & Supply Chain
- Frequently Asked Questions
Kalpataru Piping is a manufacturer and supplier of nickel alloy piping solutions of high performance, and is a specialized manufacturer of high-performance Inconel 625 seamless pipes and tubes. Inconel 625, also known as UNS N06625, is a nickel-chromium-molybdenum alloy that includes niobium, which interacts with the molybdenum to harden the matrix of the alloy and thus make it highly strong in the absence of a strengthening heat treatment. This alloy is also resistant in a broad range of highly corrosive environments, and particularly pitting and crevice corrosion.
We manufacture standard and custom sizes that strictly adhere to ASTM B444 and ASME SB444 standards. It is commonly known as Alloy 625 pipe; it is designed to be used in extreme temperature environments, both cryogenic and up to 1800°F (982°C). Under our wide variety of Inconel Products, we have ex-stock of UNS N06625 pipes and quick export to all parts of the world to supply to many industries, such as aerospace, chemical processing and marine engineering.
Introduction to Inconel 625 Superalloy
Inconel 625 (UNS N06625) is a non-magnetic corrosion and oxidation-resistant nickel-based superalloy. Its exceptional strength and hardness at temperatures between the cryogenic 2000°F (1093°C) are mainly due to the solid solution effects of the refractory metals, columbium (niobium) and molybdenum, in a nickel-chromium matrix. The alloy has a high level of fatigue strength and stress-corrosion cracking resistance to chloride ions.
The Inconel 625 pipes have been known to be highly fabricable and weldable. Inconel 625 does not need post-weld heat treatment as many other superalloys do, to retain corrosion resistance. This renders it a perfect selection in complex piping systems of the chemical plants and offshore platforms, where on-site fabrication is required.
Inconel 625 vs Other High-Temperature Alloys
Although Incoloy 825 has been optimized to make it suitable to aqueous corrosion, the Inconel 625 has better high-temperature strength and oxidation. Niobium (3.15-4.15) addition makes the alloy resistant to the sensitization process during welding to eliminate intergranular corrosion. Alloy 625 is also a high Molybdenum (8-10%) alloy, which is much more resistant to pitting and crevice corrosion than Inconel 600.
Inconel 625, when compared to Hastelloy C276, has similar corrosion resistance to Hastelloy C276 in most environments but is more fabricable and resistant to oxidation at higher temperatures, which often makes it a more useful choice in mixed-service applications.
Comparative Analysis: Inconel 625 vs Other Superalloys
| Property | Inconel 625 | Inconel 718 | Incoloy 825 | Hastelloy C-276 |
| Nickel Content | 58% min | 50-55% | 38-46% | Balance (57% typical) |
| Molybdenum | 8-10% | 2.8-3.3% | 2.5-3.5% | 15-17% |
| Max Service Temp | 1800°F (982°C) | 1200°F (649°C) | 1000°F (538°C) | 1900°F (1038°C) |
| Tensile Strength | 120 ksi (827 MPa) | 185 ksi (precipitation hardened) | 85 ksi (585 MPa) | 100 ksi (690 MPa) |
| Post-Weld Heat Treatment | Not required | Required | Not required | Not required |
| Primary Applications | Aerospace, Marine, Chemical | Gas Turbines, Nuclear | Chemical Processing | Severe Chemical Environments |
| Typical Cost (Relative) | High | Very High | Moderate | Very High |
Alloy 625 Seamless Pipe vs Welded Pipe
Kalpataru Piping provides both seamless and welded Inconel 625 pipes. The required dimensions and mechanical properties can be obtained for alloy 625 seamless pipe through extrusion or rotary piercing, then cold piloted. Seamless pipes are used in Aerospace and nuclear high-pressure and high-temperature use requires smooth pipes.
Inconel 625 welded pipes are produced on the basis of rolled plate or strip with the help of the latest welding methods. Welded pipes and the weld zone are very strong and resistant to corrosion because of the high weldability of this alloy. Flue gas desulfurization (FGD) systems and offshore risers will often make use of large-diameter welded pipes.
Welding Techniques for Inconel 625 Pipes
The outstanding weldability of Inconel 625 is one of the main benefits of this material. All the standard welding methods can be used to join the alloy without submitting the welded part to post-weld heat treatment, making fabrication simpler and less expensive.
| Welding Stage | Process | Key Considerations |
| Preparation | Material Cleaning | Remove oils, greases, marking inks, and surface contamination using acetone or alcohol |
| Fit-Up | Ensure proper alignment and gap; typical root gap: 1.6mm for GTAW backing | |
| Preheat | Generally not required; avoid excessive preheat (max 200°F / 93°C if needed) | |
| Welding Process | GTAW/TIG Welding | Preferred for root passes; use AWS ERNiCrMo-3 filler; Argon shielding gas |
| GMAW/MIG Welding | For fill and cap passes; higher deposition rate than TIG | |
| SMAW/Stick Welding | Field repairs; use ENiCrMo-3 electrodes; DC reverse polarity | |
| Submerged Arc Welding | High production welding; automatic or semi-automatic for large diameter pipes | |
| Post-Weld | Cooling | Air cool; do NOT quench in water |
| Inspection | Visual, dye penetrant, radiography, or ultrasonic testing per code requirements | |
| Cleaning | Remove slag, spatter, and heat tint; passivate if required |
Important Note: Unlike Inconel 718, Alloy 625 does NOT require solution annealing or aging heat treatment after welding. The weld zone maintains corrosion resistance equivalent to the base material.
ASTM B444 & ASME SB444 Specifications
Our manufacturing process strictly follows international standards. The primary specification for seamless pipe and tube is ASTM B444 (ASME SB444). Welded pipes typically follow ASTM B705.
Detailed Specifications for Inconel 625 Pipes & Tubes
| Specification | Details |
| Standard Specifications |
ASTM B444, ASME SB444 (Seamless) ASTM B705, ASME SB705 (Welded) ASTM B446 (Rod/Bar), ASTM B564 (Forgings) |
| Size Range (Seamless) | 1/8″ NB to 24″ NB |
| Size Range (EFW/Welded) | 6″ NB to 48″ NB |
| Schedule Thickness Range | SCH 5, SCH 10, SCH 40, SCH 80, SCH 160, SCH XXS |
| End Types | Plain End, Beveled End, Threaded |
| Inspection & Test Reports | EN 10204 3.1, Mill Test Certificates, NABL Approved Lab Reports, PMI, Ultrasonic Testing, Intergranular Corrosion Test |
a) Equivalent Grades
| Standard | Inconel 625 / Alloy 625 |
| UNS | N06625 |
| Werkstoff Nr. | 2.4856 |
| EN | NiCr22Mo9Nb |
| JIS | NCF 625 |
| BS | NA 21 |
| GOST | ЭП718 (XH75MDT) |
| AFNOR | NC22DNb |
b) Chemical Composition (% Weight)
| Element | Content (%) |
| Nickel (Ni) | 58.0 min |
| Chromium (Cr) | 20.0 – 23.0 |
| Molybdenum (Mo) | 8.0 – 10.0 |
| Niobium (Nb) + Tantalum (Ta) | 3.15 – 4.15 |
| Iron (Fe) | 5.0 max |
| Cobalt (Co) | 1.0 max |
| Manganese (Mn) | 0.50 max |
| Silicon (Si) | 0.50 max |
| Carbon (C) | 0.10 max |
| Titanium (Ti) | 0.40 max |
| Aluminum (Al) | 0.40 max |
c) Mechanical Properties (Room Temperature)
| Property | Value |
| Density | 8.44 g/cm³ (0.305 lbs/in³) |
| Melting Point | 1290 – 1350 °C (2350 – 2460 °F) |
| Tensile Strength (min) | 120 ksi (827 MPa / 930 MPa typical) |
| Yield Strength (0.2% Offset) | 60 ksi (414 MPa / 517 MPa typical) |
| Elongation (min) | 30% (42.5% typical in 50mm) |
| Elastic Modulus | 30.1 x 10³ ksi (207 GPa) |
| Poisson’s Ratio | 0.278 |
d) Physical & Thermal Properties
| Property @ Temperature | 70°F (21°C) | 400°F (204°C) | 800°F (427°C) | 1000°F (538°C) |
| Thermal Conductivity (Btu-in/h·ft²·°F) | 68 | 87 | 109 | 139 |
| Specific Heat (Btu/lb·°F) | 0.098 | 0.109 | 0.122 | 0.118 |
| Thermal Expansion (x10⁻⁶/°F) | – | 7.3 | 7.6 | 7.7 |
| Elastic Modulus (10³ ksi) | 30.1 | 28.7 | 26.9 | 25.7 |
Manufacturing Range & Dimensional Standards
Kalpataru Piping also has a strategic stock of Inconel 625 pipes to serve urgent project demands. We provide some flexibility in the lengths, with the usual random lengths to the cut-to-length sizes, depending on the project requirements. We have the manufacturing capacity that guarantees our product finishing with tight dimensional tolerances that can be used in the critical aerospace and marine markets.
Manufacturing Range for Inconel 625 Seamless Pipes
| Product Type | Outside Diameter | Wall Thickness | Length | Schedule Range |
| Inconel 625 Seamless Pipe | 1/8″ to 24″ NB (4mm to 610mm) | 0.5mm to 20mm | Single Random, Double Random, Cut Length (up to 6 meters) | SCH 5S, 10S, 40S, 80S, 160, XXS |
| Inconel 625 Welded/ERW Pipe | 6″ to 48″ NB (150mm to 1219mm) | 1.0mm to 15mm | Up to 6 meters / 26 meters (EFW) | SCH 5, 10, 40, 80 |
| Inconel 625 Heavy Wall Pipe | 10mm to 600mm OD | 2.5mm to 100mm | 0.5 to 12 meters | Custom Thick Wall |
| Inconel 625 Instrumentation Tubing | 1/16″ to 2″ OD (1.6mm to 50.8mm) | 0.010″ to 0.375″ (0.25mm to 9.5mm) | Cut to length / Coil form | Light Gauge |
Dimension Standards Compliance
- ANSI B36.10M – Welded and Seamless Wrought Steel Pipe
- ANSI B36.19M – Stainless Steel Pipe (applicable to Nickel Alloy)
- API 5L – Line Pipe Specifications
- ASME B36.19 – Factory-Made Wrought Buttwelding Fittings
Various Types of Inconel 625 Pipes & Tubes
We supply a wide configuration of N06625 pipes to suit diverse industrial applications.
| Product Description | Typical Applications |
| Inconel 625 Seamless Round Pipe | High-pressure steam lines, aerospace ducting |
| Inconel 625 Seamless Square Tube | Structural components in corrosive environments |
| Inconel 625 Rectangular Tube | Marine hardware, specialized frames |
| Inconel 625 Welded Pipe (ERW/EFW) | Pollution control, chemical processing lines |
| Inconel 625 Heat Exchanger Tubes | Shell & tube exchangers, condensers |
| Inconel 625 Instrumentation Tubing | Control lines, hydraulic systems |
Pipe Weight Chart (Common Sizes)
Below is a theoretical weight chart for Schedule 40 Inconel 625 pipes. Note that Alloy 625 (Density 8.44 g/cm³) is heavier than standard stainless steel.
| NPS (Inches) | DN (mm) | Outside Diameter (mm) | Schedule | Wall Thickness (mm) | Weight (Kg/Meter) |
| 1/2″ | 15 | 21.3 | SCH 40 | 2.77 | 1.35 |
| 3/4″ | 20 | 26.7 | SCH 40 | 2.87 | 1.80 |
| 1″ | 25 | 33.4 | SCH 40 | 3.38 | 2.68 |
| 1 1/2″ | 40 | 48.3 | SCH 40 | 3.68 | 4.33 |
| 2″ | 50 | 60.3 | SCH 40 | 3.91 | 5.82 |
| 3″ | 80 | 88.9 | SCH 40 | 5.49 | 12.06 |
| 4″ | 100 | 114.3 | SCH 40 | 6.02 | 17.18 |
| 6″ | 150 | 168.3 | SCH 40 | 7.11 | 30.20 |
| 8″ | 200 | 219.1 | SCH 40 | 8.18 | 45.48 |
Pressure Rating for Inconel 625 Pipes at Various Temperatures
Below are maximum internal working pressures (in PSI) for Inconel 625 pipes at different operating temperatures. Note that pressure ratings decrease at elevated temperatures.
| Size (mm OD x WT) | 100°F (38°C) | 200°F (93°C) | 400°F (204°C) | 600°F (316°C) | 800°F (427°C) | 1000°F (538°C) |
| 3 x 0.5 | 940 psi | 940 psi | 930 psi | 921 psi | 907 psi | 888 psi |
| 6 x 1 | 940 psi | 940 psi | 930 psi | 921 psi | 907 psi | 888 psi |
| 8 x 1 | 681 psi | 681 psi | 675 psi | 668 psi | 658 psi | 644 psi |
| 8 x 2 | 1476 psi | 1476 psi | 1462 psi | 1447 psi | 1425 psi | 1395 psi |
| 10 x 1 | 534 psi | 534 psi | 529 psi | 524 psi | 516 psi | 505 psi |
| 12 x 1 | 440 psi | 440 psi | 435 psi | 431 psi | 424 psi | 415 psi |
| 16 x 1 | 324 psi | 324 psi | 321 psi | 318 psi | 313 psi | 307 psi |
Note: Consult with our engineering team for specific pressure/temperature ratings for your application.
Need Exact Dimensions?
Access our comprehensive chart detailing OD, ID, and Wall Thickness for all schedules.
Applications & Industries Served
Inconel 625 material is widely used in industries requiring high fatigue strength and corrosion resistance under extreme conditions.
Aerospace & Gas Turbine Components
Aircraft ducting systems, engine exhaust systems, thrust-reverser systems, and turbine shroud rings utilize Inconel 625 tubes which feature high tensile, creep, and rupture strength.
Chemical Processing & Petrochemical
The alloy withstands a broad range of corrosive media, and is therefore used in reaction vessels, distillation columns, and transfer piping that deal with phosphoric acid, nitric acid and alkalines.
Marine & Offshore Applications
Alloy 625 is also used as the standard seawater component, propeller shafts and submarine auxiliary propulsion motors because of its resistance to chloride-ion stress-corrosion cracking and its very high pitting resistance.
Heat Exchanger Applications
Inconel 625 is an excellent thermal stability and corrosion resistant alloy that is suitable in applications in heat exchangers in aggressive environments.
Pollution Control & Flue Gas Desulfurization
Used in scrubbers, dampers, and stack liners in coal-fired power plants to withstand corrosive sulfur-rich flue gases.
Quality Assurance & Testing
In Kalpataru Piping, all the Alloy 625 pipes are thoroughly monitored in terms of quality to meet the requirements of ASTM B444. We are also certified vendors to leading OEMs, and our materials are Saudi ARAMCO compliant.
Comprehensive Testing Procedures
| Test Type | Standard/Method | Purpose |
| PMI Testing | Positive Material Identification | Verify Nickel (58% min), Cr, Mo, Nb content |
| Chemical Analysis | Spectro Analysis per ASTM E415 | Confirm elemental composition within specification limits |
| Mechanical Testing | ASTM A370 | Tensile Strength (min 120 ksi), Yield Strength (min 60 ksi), Elongation (min 30%) |
| Intergranular Corrosion (IGC) Test | ASTM G28 Method A | Verify resistance to sensitization after welding |
| Flattening Test | ASTM E8 | Assess ductility and detect surface defects |
| Flaring Test | ASTM E290 | Check formability and weld quality |
| Ultrasonic Testing (UT) | ASTM E213 | Detect internal defects in seamless pipes |
| Hydrostatic Testing | ASTM A999 | Verify leak-proof performance under pressure |
| 100% Radiography | ASTM E94 (for welded pipes) | Ensure weld seam integrity |
| Macro & Micro Examination | ASTM E340, E407 | Evaluate grain structure and weld penetration |
| Pitting Resistance Test | ASTM G48 Method A | Assess resistance to localized corrosion |
Documentation Provided with Every Shipment
- EN 10204 3.1 Mill Test Certificates (MTC) – Factory test certificate with manufacturer’s declaration
- Material Traceability Records – Complete heat number tracking from raw material to finished product
- Chemical & Mechanical Test Reports – NABL Approved Lab certifications
- PMI Test Reports – Positive Material Identification results
- Third Party Inspection (TPI) Reports – Available upon request from independent agencies
- Visual Inspection Reports – Surface quality verification
- Destructive & Non-Destructive Test Reports – Complete testing documentation
- Heat Treatment Charts – Annealing/solution treatment records
- Fumigation Certificates – For international shipments (ISPM 15 compliant)
- Certificate of Origin – Country of manufacture documentation
- Commercial Invoice with HS Code – 75071200 (for customs clearance)
Surface Finish Options for Inconel 625 Pipes
We offer multiple surface finishes to meet specific application requirements:
| Finish Type | Description | Typical Applications |
| Mill Finish (Rough) | As-rolled or as-extruded; no additional surface treatment | Structural applications, non-critical services |
| Annealed & Pickled | Heat treated and acid pickled to remove scale | Standard finish for most corrosive applications |
| Bright Annealed (BA) | Annealed in controlled atmosphere; shiny reflective surface | Pharmaceutical, food processing, clean room applications |
| Electropolished | Electrochemical surface removal; smoothest finish; enhanced corrosion resistance | Semiconductor, biotech, ultra-pure applications |
| Polished (#4, #6, #8 Mirror) | Mechanical polishing to specified grit; decorative and functional | Architectural, cleanroom, aesthetic applications |
| Brushed/Satin Finish | Directional grain pattern; non-reflective | Architectural, decorative applications |
| Sandblasted | Uniform matte surface; improved paint adhesion | Coated pipes, pre-paint preparation |
Packaging & Export Packing Standards
- Wooden Boxes – For smaller diameter tubes and cut-to-length pipes
- Bubble Wraps & Plastic Caps – End protection to prevent damage during transit
- Steel Strips Bundled – Secure bundling for larger diameter and longer pipes
- Seaworthy Packing – Moisture-resistant wrapping and desiccants for ocean freight
- Custom Packing – Available upon request for special handling requirements
- Marking – Heat number, size, grade, specification clearly marked on each piece
- ISPM 15 Compliant – Fumigated wooden packaging for international shipments
Export Destinations & Supply Chain
We are a premier exporter of Inconel 625 Seamless Pipes to over 40 countries. Our logistics network ensures safe and timely delivery to major industrial hubs in the Middle East, Asia, Europe, and the Americas.
Key Export Markets
| Region | Countries & Cities | Typical Delivery Time |
| Middle East | Saudi Arabia (Riyadh, Jubail, Dammam), UAE (Dubai, Abu Dhabi), Qatar (Doha), Kuwait, Oman (Muscat) | Air: 3-5 days | Sea: 15-20 days |
| Southeast Asia | Singapore, Malaysia, Indonesia, Thailand, Vietnam | Air: 2-3 days | Sea: 10-15 days |
| Europe | Germany, UK, France, Italy, Netherlands, Spain, Norway | Air: 5-7 days | Sea: 30-35 days |
| North America | USA (Houston, Los Angeles, New York), Canada (Toronto, Calgary), Mexico | Air: 7-10 days | Sea: 45-55 days |
| South America | Brazil, Argentina, Chile, Colombia, Venezuela | Air: 10-12 days | Sea: 50-60 days |
| Africa | Nigeria, South Africa, Egypt, Algeria, Kenya, Ghana, Tanzania | Air: 5-8 days | Sea: 25-35 days |
| East Asia | Japan, South Korea, Taiwan, China | Air: 3-5 days | Sea: 12-18 days |
HS Code for Customs: 75071200 (Nickel tube or pipe fittings)
Saudi ARAMCO Approved: Our Inconel 625 pipes meet ARAMCO specifications and are regularly supplied to major oil & gas projects in the Middle East.
Frequently Asked Questions
What is Inconel 625 used for?
What is the difference between Inconel 625 and 718?
Can Inconel 625 be welded?
What is the maximum temperature for Inconel 625?
Ready to Order?
Get high-grade Inconel 625 (UNS N06625) Pipes directly from the manufacturer. We offer Ex-Stock delivery for urgent shutdowns.
Contact Us for Ex-Stock Delivery
Also check: Inconel 625 Flanges | Fittings | Fasteners
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Cities We deliver:
Bhopal, Lahore, Milan, Hyderabad, Pune, Vadodara, Pimpri-Chinchwad, Aberdeen, Howrah, Jeddah, Riyadh, Bogota, Petaling Jaya, Dallas, Lagos, Nagpur, Houston, Brisbane, Busan, Karachi, Coimbatore, Seoul, Caracas, Atyrau, Perth, Haryana, Bengaluru, Jaipur, Al Jubail, Kuwait City, Al Khobar, Sydney, Ranchi, Chiyoda, Noida, Chandigarh, Secunderabad, Ahvaz, Port-of-Spain, Singapore, Gurgaon, Rajkot, Rio de Janeiro, Abu Dhabi, Hong Kong, Surat, Sharjah, Hanoi, London, Muscat, Jakarta, Navi Mumbai, Istanbul, Kolkata, Cairo, Mumbai, Santiago, Montreal, Faridabad, Vung Tau, Bangkok, Ankara, Ahmedabad, Granada, Melbourne, Tehran, Visakhapatnam, New Delhi, Los Angeles, Ho Chi Minh City, Edmonton, La Victoria, Baroda, Thane, Nashik, Kuala Lumpur, Moscow, Ernakulam, Courbevoie, Calgary, Geoje-si, Indore, New York, Mexico City, Gimhae-si, Ludhiana, Kanpur, Ulsan, Thiruvananthapuram, Manama, Doha, Chennai, Madrid, Jamshedpur, Algiers, Dammam
Countries We Deliver:
Iran, Venezuela, Saudi Arabia, Slovakia, Romania, Zimbabwe, Spain, Kazakhstan, Canada, Nigeria, Bulgaria, Afghanistan, Thailand, Bangladesh, Poland, United Kingdom, Bahrain, Jordan, Lithuania, Malaysia, France, Nigeria, Japan, Oman, Lebanon, Germany, Croatia, Australia, Puerto Rico, South Korea, Hungary, United States, Bhutan, Mexico, Mexico, Yemen, Singapore, New Zealand, Ecuador, Gabon, Qatar, Denmark, Iran, Netherlands, Norway, Sri Lanka, Belgium, Libya, Kuwait, Pakistan, Gambia, Sweden, Azerbaijan, Argentina, Chile, Ghana, United Arab Emirates, Finland, Nepal, Trinidad andamp; Tobago,Tunisia, Kenya, Peru, Austria, Russia, Ukraine, Italy, Belarus, Bolivia, Serbia, Poland, Mongolia, Turkey, Czech Republic, South Africa, Angola, India, Vietnam, Indonesia, Tibet, Ireland, Costa Rica, Greece, Colombia, Namibia, Iraq, Estonia, Israel, Macau, Philippines, Brazil, Switzerland, Algeria, Morocco, Chile, Portugal, Egypt, Taiwan, China, Hong Kong.
