Inconel 625
Fasteners & Material Data
UNS N06625 · W.Nr. 2.4856
What is Inconel 625 and its applications?
Inconel 625 (UNS N06625) is a nickel-chromium-molybdenum-niobium alloy. It is used in marine equipment, chemical plant and aerospace components that require a combination of corrosion resistance and mechanical performance.
- Marine engineering: Seawater fittings, propulsion components and instrument hardware.
- Chemical processing: Vessels, transfer piping, valves and heat exchangers.
- Aerospace systems: Ducting, exhaust and other engineered components.
Choose your 625 product
Engineering Application & Selection Guide
Molybdenum and niobium strengthen the nickel-chromium matrix by solid solution; a precipitation-hardening treatment is not required to develop its normal supplied properties. Product form and thermal condition still affect the values that can be used.
- Inconel 625 hex bolts — For marine joints, identify seawater temperature, flow, deposits and periods of stagnation.
- Inconel 625 stud bolts — For process flanges, specify material condition, required load capacity and any sour-service criteria separately.
- Inconel 625 socket head cap screws — For valve assemblies, define thread fit, compatible lubrication and the tightening method to manage galling.
Use the 625 versus 718 fastener guide to compare the required condition, corrosion behavior and strength. Choosing 625 for corrosion or 718 for strength is only a starting point, not a complete substitution rule.
Inconel 625 Composition
Composition limits · wt.%
- Ni
- ≥58%
- Cr
- 20–23%
- Mo
- 8–10%
- Nb + Ta
- 3.15–4.15%
- Fe
- ≤5%
- C
- ≤0.10%
- Mn
- ≤0.50%
- Si
- ≤0.50%
- P
- ≤0.015%
- S
- ≤0.015%
- Al
- ≤0.40%
- Ti
- ≤0.40%
- Co (if determined)
- ≤1.0%
ASTM / ASME specifications by product form
Finished-product requirements
Specify the finished-fastener mechanical requirements, condition and inspection separately from the starting-stock specification.
Inconel 625 hex bolt requirements ↗Fasteners · dimensional references
| Product | Reference |
|---|---|
| Hex bolts | ISO 4014 / ISO 4017 · ASME B18.2.1 |
| Threaded studs | DIN 976-1 · ASME B18.31.2 |
| Hex nuts | ISO 4032 · ASME B18.2.2 |
| Socket head screws | ISO 4762 · ASME B18.3 |
| Flat washers | ISO 7089 / ISO 7090 · ASME B18.21.1 |
| Custom fasteners | Customer drawing |
Raw-material specifications
| Product form / scope | Reference |
|---|---|
| Rod & bar | ASTM B446 / ASME SB446 · AMS 5666 |
| Forgings & rings | ASTM B564 / ASME SB564 · AMS 5666 |
| Wire | AMS 5837 |
| Plate, sheet & strip | ASTM B443 / ASME SB443 · AMS 5599 / 5869 · MAM 5599 |
| Seamless pipe & tube | ASTM B444 / B829 · ASME SB444 / SB829 |
| Welded tube | ASTM B704 / B751 · ASME SB704 / SB751 · AMS 5581 |
| Welded pipe | ASTM B705 / B775 · ASME SB705 / SB775 |
| Fittings | ASTM B366 / ASME SB366 |
Dimensions do not define material or finished-part compliance. Specify the grade, condition and applicable requirements.
How to specify round bar, plate, wire and strip ↗Inconel 625 Mechanical Properties
Reference sample and condition
- Data basis
- Nominal reference range
- Test sample form
- Rod, bar & plate
- Sample size
- Up to 101.6 mm
- Condition
- Solution treated
- Test temperature
- Room temperature
| Key properties | Value |
|---|---|
| Tensile strength | 724–896 MPa |
| 0.2% yield strength | 290–414 MPa |
| Elongation | 40–65% |
Inconel 625 Physical Properties
| Property | Value | Unit |
|---|---|---|
| Density | 8.44 | g/cm³ |
| Melting range | 1290–1350 | °C |
Temperature curves and values
Tensile and yield strength
Hot-rolled plate · mill annealed at 1052°C
Published table values
Haynes · 625 plate tensile data · Tensile Properties → Hot-Rolled and 1925°F (1052°C) Mill-Annealed, Plate ↗Elongation vs temperature
Hot-rolled plate · mill annealed at 1052°C
Published table values
Haynes · 625 plate tensile data · Tensile Properties → Hot-Rolled and 1925°F (1052°C) Mill-Annealed, Plate ↗Procurement and application guide
Specify the material and final condition
Match the annealed or solution-treated condition to the application.
Material forms in the technical reference: Round bar · Flat bar · Wire · Plate · Sheet · Strip · Pipe & tube · Forging stock · Hexagon & sections.
Define the finished-part acceptance
Include the material or bolting specification, required final condition, dimensions and quantity. State the service medium, temperature and loading where known. Agree the required tests, inspection coverage and acceptance criteria for the finished part.
Start with the information you have
Send a drawing or share the product form and dimensions. Identify any undecided requirements for review rather than copying a typical property value into the purchase order.
Upload DrawingCondition-specific data
Room-temperature properties by condition
Nominal ranges from Table 5.
| Reference / condition | Tensile MPa | Yield 0.2% MPa | Elongation % |
|---|---|---|---|
| Annealed · rod, bar & plate ≤101.6 mm | 827–1034 | 414–655 | 30–60 |
| Solution treated · rod, bar & plate ≤101.6 mm | 724–896 | 290–414 | 40–65 |
Catalogue minimums
A5 elongation, as labelled in the supplied table.
| Reference / condition | Tensile MPa | Yield 0.2% MPa | Elongation % |
|---|---|---|---|
| ASTM B446 catalogue row | ≥827 | ≥414 | ≥30 |
Technical guides
All technical articles ↗
How to Specify Inconel 625 Fasteners
Inconel 625 vs 718: Which Is Better for Fasteners?
Nickel-Alloy Fastener GallingSelection and specification · 3
Installation and inspection · 4
Quality documents
EN 10204 3.1 MTC
Material certification and heat-number traceability
Mechanical testing
Methods and acceptance criteria follow the agreed specification
Alloy 718 laboratory report · PDF ↗Thread inspection
Sampled GO/NO-GO gauging for threaded products
Additional inspection and records
Heat-treatment records, PMI and third-party scope agreed per order
View PMI sample ↗Specify your Inconel 625 fastener
Sources and references
- Special Metals · Alloy 625 · Tables 1, 2 & 5; Available Products and Specifications (page 17) ↗
- ASTM · B446 · B446-26 · public scope ↗
- Supplied technical reference · Scanned PDF page 4 · printed page 16
- Supplied technical reference · Scanned PDF page 12 · printed page 24
- Haynes · 625 plate tensile data · Tensile Properties → Hot-Rolled and 1925°F (1052°C) Mill-Annealed, Plate ↗
Additional published references
- DIN 17744 / 17750–17754; ISO 6207 / 6208 / 9723–9725 / 4955A; BS 3072 / 3074 / 3076 (NA21); EN 10095; VdTÜV 499; ASME Code Case 1935 Special Metals · Alloy 625 · Tables 1, 2 & 5; Available Products and Specifications (page 17) ↗
- NACE MR0175 / ISO 15156 Supplied technical reference · Scanned PDF page 12 · printed page 24