ASTM B425 UNS N08825 Round Bar | Alloy 825 Bar 2.4858
ASTM B425 UNS N08825 round bar is a nickel-iron-chromium-molybdenum-copper alloy bar used for corrosion-resistant components in chemical processing, acid service, oil and gas, marine and industrial equipment. Alloy 825 combines high nickel and chromium contents with molybdenum, copper and titanium to provide resistance to chloride stress-corrosion cracking, reducing acids, oxidizing environments, pitting and crevice corrosion.
We supply ASTM B425 / ASME SB425 UNS N08825 round bars in hot-finished, cold-drawn and annealed conditions, with custom cutting, surface processing, PMI, UT and EN 10204 3.1 certification when required.
ASTM B425 N08825 Round Bar Specification
| Item | Specification |
|---|---|
| Material Standard | ASTM B425 / ASME SB425 |
| UNS | N08825 |
| Material | Alloy 825 |
| EN / W.Nr. | 2.4858 |
| Material Family | Nickel-Iron-Chromium-Molybdenum-Copper Alloy |
| Product Forms | Round / Square / Hexagonal / Rectangular Bar |
| Condition | Hot Finished / Cold Drawn / Annealed |
| Typical Diameter Supply | 3–500 mm |
| Typical Length | 1,000–6,000 mm or cut length |
| Surface Finish | Black / Peeled / Turned / Polished / Ground |
| Certification | EN 10204 3.1 / 3.2 when specified |
What Is ASTM B425 UNS N08825?
astm-b425 covers nickel-iron-chromium-molybdenum-copper alloy rod and bar, including UNS N08825 in hot-finished and cold-drawn product forms.
The standard covers shapes including:
- Round bars
- Square bars
- Hexagonal bars
- Rectangular bars
UNS N08825 is particularly useful where a combination of corrosion resistance, mechanical strength and machinability is required.
The principal material designations are:
| System | Designation |
|---|---|
| ASTM | B425 UNS N08825 |
| ASME | SB425 UNS N08825 |
| UNS | N08825 |
| EN / W.Nr. | 2.4858 |
| Material | Alloy 825 |
Available Size Range
Typical commercial supply options include:
| Parameter | Available Range |
|---|---|
| Diameter | 3–500 mm |
| Length | 1,000–6,000 mm |
| Cut Length | Available |
| Surface | Black / Peeled / Turned / Polished / Ground |
| Condition | Annealed / Hot Finished / Cold Drawn |
Actual availability depends on diameter, manufacturing condition, tolerance, surface finish, inspection requirements and order quantity.
ASTM B425 N08825 Chemical Composition
| Element | UNS N08825 |
|---|---|
| Nickel, Ni | 38.0–46.0% |
| Chromium, Cr | 19.5–23.5% |
| Iron, Fe | Balance |
| Molybdenum, Mo | 2.5–3.5% |
| Copper, Cu | 1.5–3.0% |
| Titanium, Ti | 0.6–1.2% |
| Carbon, C | 0.05% max |
| Manganese, Mn | 1.00% max |
| Silicon, Si | 0.50% max |
| Sulfur, S | 0.03% max |
| Aluminum, Al | 0.20% max |
The Ni-Cr-Mo-Cu alloying system gives UNS N08825 resistance to both oxidizing and reducing corrosive environments.
Actual heat chemistry is reported on the Material Test Certificate.
ASTM B425 N08825 Mechanical Properties
Typical minimum room-temperature mechanical requirements for annealed, hot-finished or cold-drawn UNS N08825 bar include:
| Property | Minimum Requirement |
|---|---|
| Tensile Strength | 586 MPa / 85 ksi |
| Yield Strength | 241 MPa / 35 ksi |
| Elongation | 30% |
Mechanical properties can vary according to bar size, production condition and heat treatment.
Actual tensile, yield and elongation results are reported on the supplied MTC.
Corrosion Resistance of UNS N08825 Round Bar
UNS N08825 is selected for applications requiring resistance to a broad range of corrosive environments.
Sulfuric Acid Resistance
The combination of nickel, molybdenum and copper provides useful resistance in many sulfuric acid environments.
Phosphoric Acid Resistance
Alloy 825 is widely used for components exposed to phosphoric acid and related chemical-processing environments.
Chloride Stress-Corrosion Cracking
The relatively high nickel content provides strong resistance to chloride-ion-induced stress-corrosion cracking compared with many conventional stainless steels.
Pitting and Crevice Corrosion
Molybdenum contributes to resistance against localized corrosion, including:
- Pitting
- Crevice corrosion
- Chloride attack
Oxidizing and Reducing Environments
Chromium contributes to resistance in oxidizing environments, while molybdenum and copper improve performance in several reducing environments.
Material suitability should always be evaluated against actual temperature, chemical concentration, contaminants and process conditions.
ASTM B425 vs ASTM B564
ASTM B425 and ASTM B564 can both apply to UNS N08825 products, but they cover different product forms.
| Standard | Main Product Form |
|---|---|
| ASTM B425 | Hot-finished and cold-drawn rod and bar |
| ASME SB425 | ASME material specification for rod and bar |
| ASTM B564 | Forgings and forging stock |
| ASME SB564 | ASME material specification for forgings and forging stock |
For standard UNS N08825 round bar supply, ASTM B425 is the primary specification.
ASTM B564 is used when forged components or forging stock are specifically required.
Available Conditions & Processing
UNS N08825 round bars can be supplied with different processing conditions according to the final application.
Available options can include:
- Hot-finished bar
- Cold-drawn bar
- Annealed bar
- Peeled bar
- Turned bar
- Centerless-ground bar
- Polished bar
- Precision cut length
- Machining allowance
- Custom surface finish
Processing can be arranged according to drawing requirements, tolerance, machining allowance and final component application.
Typical Applications
ASTM B425 N08825 round bars are commonly used for corrosion-resistant machined and fabricated components.
Typical applications include:
Chemical Processing
- Sulfuric acid equipment
- Phosphoric acid equipment
- Acid-processing systems
- Pickling equipment
- Heat-exchanger components
Oil & Gas
- Valve components
- Pump shafts
- Fasteners
- Sour-service components
- Downhole equipment parts
- Corrosion-resistant machined components
Marine & Offshore
- Marine shafts
- Offshore equipment components
- Seawater-service parts
- Scrubber-system components
Industrial Equipment
- Pump components
- Valve stems
- Heat-exchanger parts
- Pollution-control equipment
- Custom corrosion-resistant machined parts
Related UNS N08825 Products
A complete N08825 piping or equipment system can include:
| Product | Typical Specification |
|---|---|
| Round Bar | ASTM B425 UNS N08825 |
| Plate / Sheet | ASTM B424 UNS N08825 |
| Pipe | ASTM B423 UNS N08825 |
| Butt-Weld Fitting | ASTM B366 UNS N08825 |
| Forged Flange | ASTM B564 UNS N08825 |
ASTM B425 N08825 round bar can be supplied together with matching plate, pipe, fittings and forged components according to project requirements.
Inspection & Certification
ASTM B425 N08825 round bar can be supplied with:
- EN 10204 Type 3.1 MTC
- EN 10204 Type 3.2 when specified
- Heat chemical analysis
- Tensile test results
- Yield-strength results
- Elongation results
- PMI
- Diameter inspection
- Length inspection
- Straightness inspection
- Roundness inspection
- Surface examination
- UT when specified
- Third-party inspection
- Full heat-number traceability
Additional dimensional and inspection reports can be supplied according to project requirements.
Frequently Asked Questions
What is ASTM B425 UNS N08825 round bar?
ASTM B425 UNS N08825 round bar is a nickel-iron-chromium-molybdenum-copper alloy bar used for corrosion-resistant industrial and machined components.
ASTM B425 covers hot-finished and cold-drawn bar in round, square, hexagonal and rectangular forms.
What are the minimum mechanical properties of N08825 bar?
Typical ASTM B425 minimum requirements include approximately 586 MPa tensile strength, 241 MPa yield strength and 30% elongation.
Actual mechanical properties are reported on the Material Test Certificate.
What is the difference between ASTM B425 and ASTM B564?
ASTM B425 covers rod and bar, while ASTM B564 covers forgings and forging stock.
For standard N08825 round bar, ASTM B425 is normally the applicable material specification.
Is Alloy 825 suitable for sulfuric acid service?
UNS N08825 is widely used in many sulfuric acid environments because of its nickel, molybdenum and copper content.
Actual suitability depends on acid concentration, temperature, contaminants and process conditions.
What size N08825 round bar can be supplied?
Typical commercial supply can range from approximately 3 mm to 500 mm diameter, with standard or custom lengths depending on condition, tolerance, surface finish and quantity.
ASTM B425 N08825 Round Bar Supplier
We supply ASTM B425 / ASME SB425 UNS N08825 round bars for chemical processing, oil and gas, offshore, marine and corrosion-resistant machined components.
Available options include:
Hot Finished / Cold Drawn / Annealed / Peeled / Turned / Ground / Cut-to-Length Round Bar
with PMI, UT, dimensional inspection and EN 10204 certification when required.
For quotation, please specify:
Material + Standard + Diameter + Length + Quantity + Condition + Surface Finish + Inspection Requirements
Example:
ASTM B425 UNS N08825 Round Bar, Ø50 × 3000 mm, Annealed, Peeled, EN 10204 3.1
