Gnee Alloy, a supplier with 18 years of experience exporting nickel-based alloys, offers Inconel 625 (UNS N06625) nickel-chromium alloy in various industrial forms, including plates, strips, bars, hexagonal bars, and tubes/fittings. The main size range extends from plates with thicknesses of 0.010–0.156 inches (approximately 0.25–4 mm) and thin strips up to 24 inches (approximately 610 mm) wide, to plates up to 4 inches (approximately 102 mm) thick; round bars are available for machining and custom processing. Seamless tubes are typically 8 inches (approximately 203 mm) in outer diameter, with larger sizes supplied as welded tubes; the tubes conform to commercial (ASTM) and aerospace (AMS) standards. When sourcing, the appropriate form should be selected based on the specific process (machining, welding, or additive manufacturing) and relevant specifications (e.g., ASTM B443/B446 or AMS). Standard inventory lists can be verified with suppliers such as Gnee Alloy.
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Inconel 625 ASTM B443 B444 B446 Standards | UNS N06625 Supplier
Inconel 625 nickel-chromium superalloy is covered by three ASTM standards based on product form: B443 (plate/sheet/strip), B444 (seamless/welded pipe), and B446 (rod/bar); all share the UNS N06625 composition (Ni ≥58%, Cr 20–23%, Mo 8–10%, Nb 3.15–4.15%). The key distinction lies in the grade: Grade 1 (annealed at approx. 871°C) is suitable for structural applications up to 593°C, whereas Grade 2 (solution annealed at approx. 1093°C) is designed for superior creep resistance at higher temperatures. Dimensional ranges include: plate thickness of 0.1–100 mm; pipe outer diameter of 4–1219.2 mm (seamless or welded options); and rod diameters from 5 mm to over 254 mm (hot- or cold-worked). Procurement specifications must clearly state the ASTM standard, grade, precise dimensions (plate thickness/width/length; pipe NPS/wall thickness or OD/wall thickness; rod diameter/length), and manufacturing method (seamless or welded); an EN 10204 3.1/3.2 material certificate is mandatory to verify chemical composition and heat numbers. Due to its complex composition and challenging processing, this alloy is costly; it is recommended to consult specialized stockist Gnee Alloy for real-time inventory, weight calculations, and technical documentation, while also monitoring how global nickel price fluctuations impact costs.
Inconel 625 Alloy Material Grade
Inconel 625 Alloy Material Grade
| Standard | Designation |
|---|---|
| UNS | N06625 |
| W.Nr. | 2.4856 |
| DIN | NiCr22Mo9Nb |
| ISO | NiCr22Mo9Nb |
General properties of Inconel 625 alloy according to three major standards
ASTM B443, B444 and B446 share the same fundamental material specifications, which form the basis of all quality acceptance for export orders.
1. Chemical Composition (UNS N06625)
All product forms must strictly comply with UNS N06625 chemical limits. This is the primary criterion for grade verification.
| Element | Content Range (wt%) | |
|---|---|---|
|
|
Nickel (Ni) | ≥ 58.0 (balance) |
| Chromium (Cr) | 20.0 – 23.0 | |
| Molybdenum (Mo) | 8.0 – 10.0 | |
| Niobium + Tantalum (Nb+Ta) | 3.15 – 4.15 | |
| Iron (Fe) | ≤ 5.0 | |
| Carbon (C) | ≤ 0.10 | |
| Manganese (Mn) | ≤ 0.50 | |
| Silicon (Si) | ≤ 0.50 | |
| Aluminum (Al) | ≤ 0.40 | |
| Titanium (Ti) | ≤ 0.40 | |
| Phosphorus (P) | ≤ 0.015 | |
| Sulfur (S) | ≤ 0.015 |
Actual PMI test chart for Gnee Alloy nickel-based alloy products
2. Standard Heat Treatment Process for Inconel 625
All three forms are typically supplied in the solution annealed condition.
| Standard Annealing Temperature Range | 1093°C – 1204°C |
| Cooling Method | Rapid cooling (water quenching or air cooling) after soaking |
| Purpose | Dissolve precipitated phases, restore ductility, and ensure stable corrosion resistance and mechanical properties |
Click to download the Inconel 625 alloy PDF datasheet
3. UNS N06625 Alloy Corrosion Testing and Other NDT
Routine orders do not include mandatory corrosion testing. For chemical, seawater and sour service applications, intergranular corrosion testing per ASTM G28 Method A or B can be added upon request.
Optional non-destructive testing: PMI (Positive Material Identification), UT (Ultrasonic Testing), surface penetration testing. Acceptance levels must be specified in the purchase contract.
4. ASTM to ASME Equivalents for Alloy 625
For pressure vessel and pressure piping projects, the ASME versions are typically required:
| ASTM Standard | ASME Standard |
|---|---|
| ASTM B443 | ASME SB-443 |
| ASTM B444 | ASME SB-444 |
| ASTM B446 | ASME SB-446 |
Technical values are nearly identical. ASME editions add pressure vessel material certification and stamping requirements, which must be confirmed in advance for petrochemical and power plant export orders.
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Explanation of the Three Major Standards for Inconel 625 and Purchasing Tips
1. ASTM B443 – Inconel 625 Nickel Alloy Plate, Sheet, and Strip
Applicable products: UNS N06625 cold-rolled sheet, hot-rolled plate and strip, classified by thickness:
Sheet / strip: thickness ≤ 4.76 mm
Plate: thickness > 4.76 mm
Room-temperature mechanical properties of Alloy 625
| Product Form | Tensile Strength Rm | 0.2% Yield Strength Rp0.2 | Elongation A |
|---|---|---|---|
| Sheet / Strip (≤4.76mm) | 690 MPa | 275 MPa | 30% |
| Plate (>4.76mm) | 690 MPa | 414 MPa | 30% |
Practical Procurement Advice from Gnee Alloy
1. The 4.76 mm thickness threshold is a frequent source of disputes. Many drawings specify only "ASTM B443" without noting the higher yield strength requirements applicable to thicker plates, leading to rejection upon inspection.
2. Thin plates typically feature a bright-annealed finish, whereas thick plates come with a hot-rolled, pickled finish. As surface roughness and dimensional tolerance standards differ between the two, they are not interchangeable.
3. Wide plates (width >1500 mm) are custom-specification items involving longer lead times and higher costs; please ensure you plan your procurement well in advance.
2. ASTM B444 – UNS N06625 Nickel Alloy Seamless Pipe & Tube
Applicable products: UNS N06625 cold-drawn and hot-extruded seamless round tubes, as well as square and special-shaped seamless tubes. The standard includes two grades with very different performance:
Grade 1: Solution annealed, coarser grain size, optimized for high-temperature creep resistance – for static high-temperature pressure service.
Grade 2: Cold-worked + annealed, finer grain size, higher strength and fatigue resistance – for ambient/medium temperature pressure and cyclic loading applications.
Room-temperature mechanical properties of inconel Alloy 625
| Grade | Tensile Strength Rm | 0.2% Yield Strength Rp0.2 | Elongation A |
|---|---|---|---|
| Grade 1 | 690 MPa | 275 MPa | 30% |
| Grade 2 | 827 MPa | 414 MPa | 25% |
Practical Procurement Advice from Gnee Alloy
1. Approximately 80% of pipe orders do not specify whether Grade 1 or Grade 2 material is required. If unspecified, Grade 1 is supplied by default; however, this can pose safety risks in applications involving fatigue loading or high-pressure conditions. Please ensure the material grade is clearly stated in your purchase order (PO).
2. The ASTM B444 standard applies only to seamless pipe and does not cover welded pipe. Heat exchanger tubes and U-bend tubes must also meet additional requirements, such as flaring, flattening, and hydrostatic testing.
3. Small-diameter precision pipes and extra-long pipes (exceeding 12 meters in length) are custom products; please verify the manufacturer's production capacity and lead times before placing an order.
3. ASTM B446 – Alloy 625 Bar, Rod & Shapes
Applicable products: UNS N06625 hot-rolled, cold-drawn and forged round bar, square bar, hex bar, flat bar and profiles. It is the core procurement standard for fasteners, shafts, valve stems and machined components.
Room-temperature mechanical properties of Alloy 625 (annealed condition)
| Product Form | Tensile Strength Rm | 0.2% Yield Strength Rp0.2 | Elongation A |
|---|---|---|---|
| Hot-rolled / Annealed bar | 690 MPa | 275 MPa | 30% |
| Cold-drawn bar | Higher strength range, subject to mill MTR | - | - |
Practical Procurement Advice from Gnee Alloy
1. Among the three product forms, bars offer the highest level of customizability. Diameter tolerances, surface conditions (black bar, rough turned, ground, cold-drawn), and grain size must all be clearly specified.
2. Aerospace orders typically require compliance with the AMS 5666 standard; this standard imposes stricter requirements regarding grain size, cleanliness, and inspection compared to ASTM B446, so commercial-grade bars cannot be used as direct substitutes.
3. For large-diameter bars (>200 mm), the uniformity of the internal microstructure tends to decrease. If ultrasonic testing (UT) is required, it is essential to reach a prior agreement on grain size and testing sensitivity to avoid rejection due to non-compliance with acceptance criteria.
Comparison Table of the Three Major Standards: Core Differences of Inconel 625
| Comparison Item | ASTM B443 | ASTM B444 | ASTM B446 |
|---|---|---|---|
| Product Form | Plate, sheet, strip | Seamless pipe & tube | Round bar, square bar, profiles, forged bar |
| Key Mechanical Minimum | UTS ≥690 MPa; sheet yield ≥275 MPa, plate yield ≥414 MPa | Grade 1 yield ≥275 MPa; Grade 2 yield ≥414 MPa | Annealed yield ≥275 MPa; cold-drawn has higher strength |
| Minimum Elongation | 30% | Grade 1: 30% / Grade 2: 25% | 30% |
| Typical Supply Condition | Solution annealed; bright annealed for thin sheet | Grade 1: solution annealed / Grade 2: cold-drawn + annealed | Hot-rolled annealed, rough-turned, cold-drawn, ground |
| Primary Applications | Vessel shells, plate heat exchangers, structural panels | Heat exchanger tubes, process piping, high-pressure lines | Fasteners, shafts, valve stems, machined parts |
| Common Acceptance Pitfall | Confusing yield strength between thin sheet and heavy plate | Missing grade specification leading to performance mismatch | No agreed UT inspection and grain size requirements |
Gnee Alloy's Procurement Guide for Alloy 625 Products
1. 7 Mandatory Parameters for Your Purchase Order
Based on 18 years of experience with export orders, a complete specification for Inconel 625 must include the following details to eliminate 90% of potential disputes between supplier and buyer:
Full standard number + year version (e.g., ASTM B443-24)
Full dimensions (thickness / OD × ID × length, including tolerance requirements)
Supply condition and surface finish (solution annealed / cold-drawn, pickled / bright / rough-turned / ground)
For tube and bar: specify grade and grain size requirements
Additional inspection items (intergranular corrosion, UT, PMI, hydro test, etc.)
Certification requirements (mill MTR, third-party inspection report, ASME stamping, etc.)
Special service requirements (NACE sour service, low-temperature impact, etc.)
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2. UNS N06625 Typical Application Material Selection Recommendations
High-temperature static service (>800°C, e.g. furnace parts, high-temperature vessels): Prioritize B443 heavy plate and B444 Grade 1 tube – coarser grain delivers better creep resistance.
Seawater / chloride environments (heat exchangers, marine engineering): All three forms are suitable. Ensure solution annealed condition and qualified intergranular corrosion test; pay special attention to weld corrosion risk for tubular products.
High-strength fasteners and shafts: Machine from B446 bar; cold-drawn bar can be selected for higher strength. If tensile strength >1000 MPa is required, we recommend switching to Inconel 718 – 625 cannot reach this level via heat treatment.
Pressure vessels and piping: Select ASME SB series equivalents directly to ensure compliance with ASME Boiler & Pressure Vessel Code.
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Gnee Alloy 625 Quality Assurance and Inspection Procedures
Gnee Alloy 625 Inspection Procedures
We implement a 3-stage quality control system to ensure every shipment meets your specification:
Incoming mill verification: Full-element spectral analysis and mechanical property validation per heat
In-process monitoring: Dimensional, surface and tolerance inspection during custom processing
Final shipment inspection: Final verification of dimensions, surface quality and documentation
All orders are shipped with a complete, heat-number-traceable Mill Test Report. Third-party inspection by SGS, TÜV, BV and other authoritative bodies is available upon request.
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How to Select the Right Standard for Alloy 625
| Required Product | Recommended Standard |
|---|---|
| Plate | ASTM B443 |
| Sheet | ASTM B443 |
| Strip | ASTM B443 |
| Seamless Pipe | ASTM B444 |
| Seamless Tube | ASTM B444 |
| Round Bar | ASTM B446 |
| Forged Bar | ASTM B446 |
| Hex Bar | ASTM B446 |
Selecting the right product standards during the initial phase of a project helps minimize procurement errors, shorten delivery lead times, and enhance material traceability.
Contact us now for the latest 2026 export prices for Inconel 625
Why choose us as your Inconel 625 supplier with 18 years of industry experience?
✅️Direct supply with consistent quality: We maintain long-term strategic partnerships with top-tier alloy manufacturers, ensuring consistent chemical composition and stable raw material supplies-even during periods of market volatility.
✅️In-house customization capabilities: Our facilities feature precision sawing, CNC turning, controlled-atmosphere heat treatment, and centerless grinding lines, allowing us to meet specific customer requirements regarding dimensions, surface finishes, and heat treatment processes.
✅️Extensive stock and rapid delivery: We maintain a year-round inventory of over 2,000 tons of nickel alloy plates, pipes, bars, and forgings. Most standard Inconel 625 products can be shipped within 48 hours.
✅️Export compliance and global logistics: We handle all export documentation, customs compliance, and global shipping arrangements, serving clients in over 30 countries across sectors such as aerospace, oil & gas, and chemicals.
✅️End-to-end technical support: Our in-house engineering team offers complimentary grade comparisons, material selection advice, and processing guidance to help you mitigate project risks and reduce manufacturing costs.
Gnee Alloy Inconel 625 Certificate
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📦 Packaging and Shipping
All Nickel Based Alloy products are packaged using the following methods:
Wooden pallets or crates
Moisture-proof packaging
Labels with furnace number, standard, and size labels
Shipped worldwide by sea, air, or express
Gnee Alloy Alloy 625 Product Packing
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⚒️Gnee Alloy Production Line Equipment and Product Testing
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Click to request a custom quote for Gnee Alloy Inconel 625 products
Whether you require standard stock items or Inconel 625 products custom-machined to precise specifications, we are ready to support your project.
To receive a prompt and detailed quote, please provide the following information:
Product form and ASTM standard (e.g., ASTM B446 bar)
Complete dimensions and tolerance requirements
Supply condition and surface finish specifications
Quantity and delivery destination
Any special certification or testing requirements (e.g., NACE, AMS, UT, etc.)
FAQ
Q: What is the main difference between ASTM B443, B444 and B446?
A: They cover different product forms of the same UNS N06625 alloy: B443 for plate/sheet, B444 for seamless tube, B446 for bar and shapes. They share the same chemistry but have different mechanical thresholds and inspection rules.
Q: Do you supply Inconel 625 compliant with NACE MR0175?
A: Yes. We offer NACE MR0175 / ISO 15156 compliant material for sour oil & gas service. Please state this requirement when requesting a quote.
Q: Can you provide ASME SB-grade material with stamping?
A: Yes. We supply ASME SB-443, SB-444 and SB-446 material with proper certification and stamping for pressure vessel projects.
Q: What is the lead time for custom sizes?
A: Standard stock items ship within 48 hours. Custom sizes and special grades typically take 3–6 weeks depending on specification. Contact us for an exact lead time.
