When engineers and buyers ask us about 2205 duplex stainless steel bolts, they usually want clear answers to a few questions:
Will these bolts handle chloride-rich environments? Are they stronger than 316L? Do they comply with NACE and offshore standards? Can we get them in the exact size, thread, and spec we need—on time?
Our 2205 duplex stainless steel bolts are designed for exactly these situations: high chloride, high stress, and high reliability.
Core Features and Material Grades
We produce 2205 duplex bolts in the main international grades:
- UNS S32205 / UNS S31803 duplex stainless steel
- EN 1.4462
- Typical product forms: SAF 2205 hex head bolts, 2205 duplex stud bolts, EN 1.4462 threaded rods, 2205 stainless socket cap screws, and matching duplex steel 2205 washers and nuts
Key features you get:
- High strength – roughly 2× the yield strength of 316L
- Excellent pitting and crevice corrosion resistance in chlorides and seawater
- Good weldability and fabricability for special fastener designs
- Stable performance in sour service when specified to NACE MR0175 / ISO 15156
We supply precision machined 2205 bolts and custom 2205 duplex stainless steel bolts for both standard and project-specific requirements.
Balanced Duplex Microstructure and Alloying Elements
2205 duplex stainless steel has a balanced duplex microstructure of roughly 50% ferrite and 50% austenite. This structure gives a combination of:
- High strength (from ferrite)
- Good toughness and corrosion resistance (from austenite)
Typical alloying elements include:
- Cr: ~22% – base corrosion resistance
- Ni: ~5–6% – toughness and ductility
- Mo: ~3% – pitting / crevice corrosion resistance
Technical Specifications of 2205 Duplex Stainless Steel Bolts
We produce 2205 duplex stainless steel bolts to tight international standards, focusing on consistent metallurgy, accurate threads, and repeatable torque performance.
Standard Bolt Sizes and Dimensions
We supply both metric and imperial sizes as standard:
| Standard | Size Range (Metric) | Size Range (Imperial) | Length Range |
|---|---|---|---|
| ISO 4014 / 4017 | M6 – M36 (larger on request) | 1/4″ – 1½” | 20 mm – 300 mm |
| DIN 931 / 933 | M8 – M48 | – | Up to 400 mm |
| ANSI B18.2.1 | – | 3/8″ – 2″ | 1″ – 12″ |
- Tolerances follow ISO, DIN, or ANSI standards as specified.
- Special lengths, extra-long studs, and machined shoulders are available on request.
Available Bolt Types and Configurations
We support most industrial 2205 duplex fastener designs:
- Hex head bolts and cap screws (SAF 2205 hex head bolts)
- Heavy hex bolts and flange bolts
- Stud bolts and threaded rods (EN 1.4462 threaded rods, ASTM A182 F51 duplex bolts)
- Socket head cap screws (2205 stainless socket cap screws)
- U-bolts, J-bolts, and eye bolts (duplex 2205 U bolts and eye bolts)
- Washers and nuts matched to the same duplex grade
For projects needing flanges and related components in similar grades, we also offer custom alloy steel flanges and precision parts.
Thread Forms and Threading Standards
We machine threads with controlled surface finish for reliable preload:
- Thread forms:
- Metric: ISO metric coarse and fine (M)
- Imperial: UNC, UNF, 8UN
- Standards:
- ISO 261 / ISO 965
- ASME B1.1 (Unified)
- Custom threads, partial threading, and interference fits available for special designs.
Mechanical Properties of 2205 Duplex Bolts
Typical room-temperature mechanical data for solution annealed 2205 (UNS S32205 / S31803):
| Property | Typical Value* |
|---|---|
| Tensile Strength Rm | 620 – 880 MPa |
| Yield Strength Rp0.2 | ≥ 450 MPa |
| Elongation (A5) | ≥ 25% |
| Hardness | ~ 255 HB max (≈ 27 HRC) |
| Impact Toughness (–40 °C) | High, no brittle transition |
| Service Temperature Range | –50 °C to +300 °C (typical) |
*Exact values depend on bar size, product form, and final heat treatment. Our in-house testing and quality control ensures properties meet the specified standard (e.g., ASTM, EN).
Chemical Composition of 2205 Duplex Stainless Steel
We strictly control the alloy chemistry to guarantee duplex microstructure and corrosion resistance (UNS S32205 typical):
| Element | Content (wt.%) |
|---|---|
| C | ≤ 0.03 |
| Cr | 21.0 – 23.0 |
| Ni | 4.5 – 6.5 |
| Mo | 2.5 – 3.5 |
| N | 0.14 – 0.20 |
| Mn | ≤ 2.0 |
| Si | ≤ 1.0 |
| P, S | ≤ 0.03 each |
| Fe | Balance |
- PREN (Pitting Resistance Equivalent Number) typically ≥ 35, giving strong resistance to chlorides and aggressive media.
- We can match UNS S31803 chemistry when required for specific project specs or backward compatibility.
Manufacturing Process of 2205 Duplex Stainless Steel Bolts
The production of 2205 duplex stainless steel bolts begins with careful raw material selection. Only high-quality alloy steel is chosen to meet the required specifications for duplex stainless steel, ensuring the final product has the desired strength, corrosion resistance, and durability. Metallurgical control is essential during this stage to maintain precise alloy composition, which directly impacts the performance of the bolts in challenging environments.
The next step is the hot forging and forming of 2205 bolt blanks. This process involves heating the material to a high temperature and shaping it into the rough form of the bolt. The hot forging process improves the material’s mechanical properties, ensuring superior strength and resistance to wear and tear. After forming, the bolts are further processed through CNC machining and threading to achieve precise dimensions and threading patterns, enabling them to fit perfectly in their intended applications.
Once the bolts are machined, they undergo heat treatment and solution annealing. This critical step enhances the material’s mechanical properties by reducing stress and ensuring optimal hardness and ductility. After heat treatment, the bolts are subjected to surface finishing processes, such as pickling and passivation, to remove any surface impurities and enhance corrosion resistance.
Finally, non-destructive testing (NDT) and quality checks are conducted to ensure that the 2205 duplex bolts meet industry standards. These tests detect any internal flaws or inconsistencies in the material, ensuring reliability in service. Additionally, customization options are available, allowing for specific bolt sizes, threading, and other features tailored to customer needs. Lead times for production are optimized to meet delivery deadlines while maintaining high-quality standards.
For more details on the manufacturing process and precision machining of 2205 duplex bolts, visit our machining services page.
Applications and Industries for 2205 Duplex Stainless Steel Bolts
We produce 2205 duplex stainless steel bolts for customers who need high strength and real corrosion resistance, not just “stainless” on paper. Below is how our UNS S32205 / S31803 (EN 1.4462) fasteners are used in different industries, and how they stack up against 316L.
Oil and Gas Applications for 2205 Duplex Bolts
2205 duplex bolts are now a standard choice in upstream, midstream, and downstream oil and gas.
Typical uses:
- Subsea flange stud bolts and nuts
- Xmas tree and wellhead connections
- Manifolds, spools, and pipeline clamps
- Offshore platform structural bolting
- Sour service (H₂S + chlorides) with NACE MR0175 / ISO 15156 compliance
Why oil & gas buyers choose 2205:
- High strength → smaller bolt sizes for same load vs 316L
- High PREN (~35) → strong pitting and crevice corrosion resistance
- Good SSC/SCC resistance in sour and high‑chloride environments
If you work in upstream or subsea projects, you’ll likely pair our duplex bolts with other oil and gas corrosion‑resistant components similar to those used in demanding oil and gas service conditions.
Chemical Processing and Petrochemical Use Cases
In chemical plants and refineries, 2205 duplex fasteners are used wherever chlorides + pressure + temperature come together:
- Heat exchanger and pressure vessel flanges
- Reactor and column bolting
- Pump and valve bolting in chloride‑bearing media
- Storage tanks and loading arms in aggressive chemicals
Why plant engineers specify 2205:
- Better resistance than 316L in chloride‑rich, mildly acidic media
- Reduced risk of stress corrosion cracking compared with austenitic grades
- Lower life‑cycle cost vs. exotic alloys in many environments
Marine and Desalination Environments
2205 duplex stainless steel bolts are a go‑to for seawater and splash zone conditions.
Key applications:
- Seawater intake structures and screens
- Desalination plant high‑pressure pipe flanges
- Shipbuilding and marine engineering equipment
- Offshore platforms, jetties, and port structures
Benefits:
- Much higher pitting resistance than 316L in seawater
- Good performance in cyclic wet/dry and splash zones
- Suitable for marine hardware, structural bolting, and flange connections similar to what’s used across advanced marine engineering projects.
Power Generation and Energy Projects
For power and energy, 2205 duplex bolts are used where high stress and corrosion meet:
- Flue gas cleaning systems (FGD)
- Cooling water system flanges and pump bolting
- Geothermal plant piping and wellhead connections
- Renewable energy structures in marine/coastal areas (offshore wind, tidal)
Why EPCs like 2205:
- High yield strength → fewer or smaller fasteners to reach design loads
- Strong performance in chloride‑contaminated cooling water
- Good fatigue resistance under vibration and cyclic loading
Pulp and Paper Industry Applications
Pulp and paper mills push stainless grades hard with chloride + chemicals + heat. 2205 duplex bolts are widely used in:
- Digesters and bleach plant equipment
- Washer, evaporator, and heat exchanger flanges
- Piping systems handling white, green, and black liquor
Advantages vs 316L in mills:
- Better resistance to chloride + alkali + temperature combinations
- Longer service life in bleaching and recovery areas
- Reduced unplanned downtime from bolt failures
2205 Duplex vs 316L Stainless Steel Bolts – Quick Comparison
| Property / Feature | 2205 Duplex Stainless Steel Bolts | 316L Stainless Steel Bolts |
|---|---|---|
| Microstructure | Duplex (roughly 50% ferrite / 50% austenite) | Fully austenitic |
| Typical PREN | ~35 | ~24 |
| Yield strength | ~2× higher than 316L | Lower |
| Pitting resistance in seawater | Significantly better | Limited, especially in warm, high‑chloride water |
| Stress corrosion cracking (SCC) | Much better resistance | More prone in chlorides at elevated temps |
| Typical bolt size for same load | Smaller / fewer required | Larger / more required |
| Material cost | Higher per kg | Lower per kg |
| Life‑cycle cost in harsh service | Often lower (longer life, fewer failures) | Often higher due to more frequent replacement |
| Best use case | Offshore, chemical, high‑chloride, sour service | Mild industrial, non‑critical, lower chloride |
Bottom line:
- If your environment is mild and cost is the only driver → 316L can work.
- If you’re dealing with seawater, chlorides, sour gas, or high loads → 2205 duplex bolts give you much better safety margin and service life.
We supply standard and custom 2205 duplex stainless steel bolts (hex, studs, socket cap screws, U‑bolts, eye bolts, threaded rods) for global customers who need reliable performance in exactly these environments.
Key advantages of 2205 duplex stainless steel bolts
When I choose 2205 duplex stainless steel bolts for demanding projects, I’m doing it for performance, not marketing. This grade simply delivers better strength and corrosion resistance than standard austenitic grades like 304/316L, especially in harsh, chloride-rich and offshore environments.
Corrosion resistance & pitting performance of 2205 bolts
2205 duplex (UNS S32205 / S31803, EN 1.4462) is designed for aggressive media:
- High PREN (~35–38) gives real resistance to pitting and crevice corrosion in seawater and chloride environments.
- Much better pitting resistance than 316L, especially in splash zones, subsea joints, cooling water lines and desalination systems.
- Strong resistance to stress corrosion cracking (SCC) in hot chloride service, where austenitic bolts often fail early.
- Suitable for sour service when produced to NACE / ISO 15156 requirements and correctly heat-treated.
For complex, corrosive parts produced near the bolted joints, we often match 2205 bolts with our own precision-cast duplex components to avoid galvanic mismatch and premature failure. You can see how we handle corrosive alloys in our precision casting services for stainless and duplex alloys.
Mechanical strength, fatigue & durability benefits
2205 duplex bolts give higher mechanical performance than common stainless:
- Yield strength roughly 2× 316L, so you can use smaller diameters or fewer bolts for the same load.
- High fatigue strength under cyclic loads, ideal for pumps, flanges, clamps and rotating equipment.
- Better resistance to galling than many austenitic grades when properly lubricated and finished.
- Stable strength even at elevated temperatures within the recommended service range.
This combination of strength and corrosion resistance is why I push 2205 for critical flanges, pressure-retaining joints and offshore structures.
Quality assurance for 2205 duplex stainless steel bolt production
We run 2205 duplex stainless steel bolt production with strict quality control from melt to final packing. Every batch of UNS S32205 / UNS S31803 duplex fasteners is produced under documented procedures, with heat numbers, material certificates, and test records kept for full traceability. Our goal is simple: stable microstructure, certified mechanical properties, and repeatable performance in real, harsh service conditions.
Process control and metallurgical validation
For 2205 duplex stainless steel bolt production, we focus on tight process control:
- Controlled chemistry – we verify the 2205 chemical composition (Cr, Ni, Mo, N balance) by spectrometer before forging.
- Duplex microstructure check – we confirm the ferrite–austenite balance (typically 40–60% ferrite) by metallographic examination to ensure proper corrosion resistance and toughness.
- Heat treatment validation – solution annealing temperature and cooling rate are logged and monitored so every ASTM A182 F51 / EN 1.4462 bolt reaches the required phase balance and PREN ≥ 35.
If you want to see how we handle metallurgical development and testing across alloys, you can look at our duplex-focused R&D and process technology approach.
Inspection, traceability, and certification documentation
We treat inspection and documentation for 2205 duplex bolts the same way our oil & gas and marine clients expect for critical fasteners:
- Dimensional and visual inspection on 100% of safety‑critical items (hex bolts, stud bolts, threaded rods).
- Mechanical tests (tensile, yield, elongation, hardness, impact when required) by lot, according to ASTM/EN/ISO standards.
- NDE options – ultrasonic, dye penetrant (PT), magnetic particle (where applicable) and PMI for material mix‑up prevention.
- Full traceability – each bolt is linked back to heat number, batch, and process route.
- Certification package – mill test certificates (EN 10204 3.1 / 3.2 on request), NACE MR0175 / ISO 15156 compliance statements for sour service, plus any client‑specific inspection reports.
Our production and inspection lines are set up for international buyers; you can review our facilities and inspection workflow in our factory overview.
Performance results and real-world case applications
Our 2205 duplex stainless steel bolts are already running in:
- Offshore platforms and subsea equipment – replacing 316L bolts where pitting and crevice corrosion in chlorides were a problem.
- Desalination and seawater systems – long‑term stable performance under continuous chloride exposure.
- Chemical and petrochemical plants – flange connections and pumps in chloride‑bearing and mildly sour media.
In these projects, 2205 duplex bolts have delivered:
- Lower failure rate versus austenitic grades in cyclic loading and corrosive conditions.
- Extended service life and fewer shutdowns for bolt replacement.
- Proven compliance with client specs, third‑party inspections, and global standards like API and NORSOK where required.
We build our quality assurance system around these real‑world results, so when you specify 2205 duplex stainless steel fasteners, you know exactly what performance level you’re buying.
Pricing and availability of 2205 duplex stainless steel bolts
Price factors for 2205 duplex fasteners
I price 2205 duplex stainless steel bolts based on a few clear factors:
| Factor | What changes the price |
|---|---|
| Material grade | UNS S32205 / S31803, certified melt, NORSOK / NACE compliant |
| Size & length | Larger diameters, long studs, non‑standard lengths cost more |
| Bolt type | Hex bolts, stud bolts, socket caps, U bolts, eye bolts, threaded rod |
| Order volume | Bulk orders lower unit price; small batches cost more per piece |
| Specs & testing | Extra NDT, 3.2 certs, coatings (PTFE, HDG alt), special QA |
| Finish & coating | Pickled & passivated, blasted, PTFE coated, lubricated threads |
| Lead time | Standard lead time is cheaper than rush production |
I’m not trying to be the cheapest; I focus on stable quality, full traceability, and predictable lead times.
Standard size availability and stocking programs
For 2205 duplex bolts and threaded rods, I keep a practical stock range for fast delivery:
| Item | Range (typical) | Standards |
|---|---|---|
| Hex bolts | M8–M36 / 5/16″–1-1/2″ | DIN 931 / 933, ISO 4014 / 4017, ANSI B18.2.1 |
| Stud bolts | M10–M36 / 3/8″–1-1/2″ | ASTM A182 F51, B16.5 / B16.47 flange studs |
| Threaded rod | M10–M36, 1 m–3 m | EN 1.4462 threaded rods |
| Nuts & washers | Matching sizes | DIN / ISO / ANSI |
For regular users (oil & gas, marine, chemical plants), I offer stocking programs:
- Fixed safety stock in 2205 duplex at agreed sizes
- Call-off orders for projects, with reserved production slots
- Priority on repeat sizes for your standard BOMs
Custom 2205 bolt orders and global shipping options
If you need custom 2205 duplex stainless steel bolts, I support:
- Custom designs: special heads, non-standard lengths, step bolts, flange bolts
- Custom threading: UNC/UNF, metric fine, ACME, partial or full thread, double end studs
- Special parts: duplex 2205 U bolts, eye bolts, foundation bolts, precision machined 2205 screws
Global shipping options:
- Sea freight for bulk and project packages
- Air freight / courier for urgent maintenance and shutdown orders
- Export-ready packing with heat and corrosion resistant packing and full marking
- Familiar with offshore, refinery, and marine documentation and packing requirements
Technical documents, drawings, and data sheets for 2205 bolts
I support engineering and QA teams with clear documentation:
- Dimensional drawings: PDF / CAD for standard and custom 2205 duplex bolts
- Material data sheets: 2205 duplex stainless (UNS S32205 / S31803, EN 1.4462)
- MTC / Mill Test Certificates: EN 10204 3.1 / 3.2 with heat number traceability
- Test reports: mechanical properties, hardness, PMI, NDT, corrosion tests (where agreed)
- Compliance papers: NACE MR0175 / ISO 15156, ASTM, ASME, API, if specified in PO
If you send me your spec sheet or drawing, I’ll quote price, lead time, and available documentation in one clear package.
Frequently Asked Questions About 2205 Duplex Stainless Steel Bolts
Machinability and Fabrication of 2205 Bolts
2205 duplex stainless steel is harder to machine than 304/316, but with the right setup it’s very manageable.
For precision machined 2205 bolts, we typically use:
- Rigid CNC machines with high-power spindles
- Slower cutting speeds, higher feed, and sharp carbide tools
- Plenty of coolant to control heat and avoid work hardening
Welding, bending, and forming are also possible, but they must follow duplex stainless procedures to keep the duplex microstructure balanced and the corrosion resistance intact. That’s why we control every step in-house from raw material to finished fastener, just like we do for our other alloy steel parts in our precision casting and forging operations.
Use of 2205 Duplex Bolts in Sour Gas and Chloride Environments
2205 duplex stainless steel bolts are designed for harsh media:
- Suitable for H₂S / sour service when manufactured and heat-treated to NACE MR0175 / ISO 15156
- High resistance to chloride pitting and crevice corrosion (PREN ~35)
- Widely used in offshore platforms, subsea equipment, desalination plants, and chemical lines
If you’re specifying for sour gas, we match:
- Hardness limits
- Microstructure control
- Impact toughness and SSC/SCC (sulfide stress cracking) requirements
Custom Threading and Special Bolt Designs
We produce custom 2205 duplex stainless steel fasteners tailored to project-specific requirements. Our capabilities include:
-
Non-standard thread forms (UN/UNR, Metric, ACME, API, and custom pitch)
-
Special head geometries, extended shanks, and engineered load-bearing designs
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Precision machining for tight tolerances in high-pressure or subsea assemblies
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Coatings and surface treatments compatible with sour service
-
Full material traceability, MTR documentation, and third-party inspection upon request
Whether you need prototype quantities or large-volume production, we can manufacture 2205 duplex bolts optimized for sour gas, chloride-rich environments, or demanding mechanical performance.
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