High Mechanical Strength
Duplex stainless steels provide substantially higher proof strength than conventional austenitic grades, supporting high-load bolting and efficient structural designs.
Specialty Alloy Fasteners
Duplex Stainless Steel Fasteners Manufacturer
High-strength duplex stainless steel bolts, stud bolts and custom fasteners engineered for chloride-bearing, chemical and high-load industrial applications.
Lean & Standard Duplex Expertise
Duplex 2304 and 2205 fasteners for moderate-to-demanding corrosion and high-load applications.
High Strength & Chloride Resistance
Duplex microstructures combine elevated proof strength with strong resistance to chloride stress corrosion cracking.
Custom Manufacturing
Standard and drawing-based duplex fasteners manufactured to project-specific dimensions and requirements.
Overview
Duplex Stainless Steel Fasteners for Corrosive & High-Load Environments
Duplex stainless steels have a mixed austenitic-ferritic microstructure that provides a combination of high mechanical strength, good toughness and strong corrosion resistance. Compared with conventional austenitic stainless steels, duplex grades can provide approximately twice the proof strength together with improved resistance to chloride stress corrosion cracking, pitting and crevice corrosion. Duplex 2304 is a lean duplex grade designed for moderate corrosion and high-strength structural service. Duplex 2205 is a more highly alloyed standard duplex family used in more demanding chloride, chemical, oil and gas environments. The exact UNS grade—S31803 or S32205—should always be identified in the purchase specification and MTC.
Why Choose This Material
Why Duplex Stainless Steel Is Selected for Critical Fastening Applications
Duplex stainless steel combines high strength, chloride resistance and long-term durability for demanding industrial fastening systems.
Chloride Stress Corrosion Resistance
The duplex microstructure provides strong resistance to stress corrosion cracking in chloride-bearing environments where conventional stainless steels may be more vulnerable.
Pitting & Crevice Corrosion Resistance
Chromium, molybdenum and nitrogen improve resistance to localized corrosion in seawater, brackish water and chemical process environments.
Grade & Specification Flexibility
Duplex 2304 and the 2205 family provide different balances of alloy content, corrosion performance, strength and product-form specification.
Duplex Stainless Steel Grades Available for Fasteners
Duplex 2304 and the 2205 family cover different requirements for high strength, chloride resistance and corrosion-resistant industrial fastening.
Duplex 2304 / S32304
UNS:
S32304
EN / W.Nr.:
1.4362
ASTM A182 Forging Grade:
F68
Standards
- ASTM A276
- ASTM A479
- EN 10088-3
Characteristics
- High strength with lean alloy content
- Good chloride SCC resistance
- Good general corrosion resistance
Applications
Desalination, Structural components, Storage tanks, Heat exchangers
Duplex 2205
UNS:
S31803 / S32205
EN / W.Nr.:
1.4462
ASTM A182 Forging Grades:
F51 / F60
Standards
- ASTM A276
- ASTM A479
- EN 10088-3
Characteristics
- High mechanical strength
- High chloride SCC resistance
- High pitting and crevice resistance
Applications
Oil & gas, Chemical processing, Offshore equipment, Marine systems
Other Duplex Stainless Steel Grades Available
Additional lean and standard duplex grades can be reviewed according to customer drawings, project specifications and actual service conditions.
Chemical Composition of Duplex Stainless Steel Grades
Compare the principal alloying elements of Duplex 2304 and 2205 and how they influence strength and corrosion performance.
| GRADE | CR (%) | NI (%) | MO (%) | N (%) | C (%) | OTHER (%) |
|---|---|---|---|---|---|---|
| Duplex 2304 / S32304 | 22.5 | 4.5 | 0.3 | 0.100 | 0.030 max | Cu 0.30, Mn 2.0 max, Si 1.0 max |
| Duplex 2205 — Nominal Reference | 22.5 | 5.5 | 3.2 | 0.180 | 0.030 max | Mn 2.0 max, Si 1.0 max |
Reference values are provided for general comparison only. The governing material specification and batch MTC take precedence for production and acceptance.
Mechanical Performance of Duplex Stainless Steel Grades
Duplex grades provide substantially higher proof strength than conventional austenitic stainless steels while retaining useful ductility.
| GRADE / CONDITION | TENSILE STRENGTH (MPa) | 0.2% YIELD STRENGTH (MPa) | ELONGATION (%) |
|---|---|---|---|
| 2304 / S32304 — Annealed Bar Reference | 600 min | 400 min | 25 min |
| 2205 / S31803 — Annealed Bar Reference | 620 min | 448 min | 25 min |
| 2205 / S32205 — Annealed Bar Reference | 655 min | 450 min | 25 min |
Mechanical properties depend on product form, dimensions, material condition, heat treatment and the applicable specification. The purchase specification and actual inspection certificate shall govern the order.
Duplex Stainless Steel Grade Selection Guide
Choose Duplex 2304 for moderate corrosion and structural service, and 2205 for more demanding chloride and chemical environments.
| Application Requirement | Recommended Grade |
|---|---|
| Moderate corrosion and structural service | Duplex 2304 / S32304 |
| Lean-alloy, high-strength duplex solution | Duplex 2304 / S32304 |
| General chloride-bearing environments | Duplex 2205 |
| Chemical processing and heat exchangers | Duplex 2205 |
| Oil & gas and offshore equipment | Duplex 2205, subject to project requirements |
| Sour-service application | Exact 2205 grade and condition must comply with NACE / ISO 15156 and project requirements |
| ASTM A182 forged material requirement | S32304/F68, S31803/F51 or S32205/F60, as specified |
| Severe seawater or highly aggressive chloride service | Evaluate a suitable Super Duplex grade |
Duplex Stainless Steel Fastener Product Range
Duplex fasteners are available in standard and custom configurations for offshore, chemical, marine and high-load industrial applications.
Hex Bolts
Product Type: Hex Head Bolts / Full Thread Hex Bolts / Partial Thread Hex Bolts / Custom Hex Bolts
Size Range: Standard / Custom
Thread System: Metric / UNC / UNF
Thread Type: Coarse / Fine
Standard: Dimensional Standards: ISO / DIN / ASME, as applicable, or customer drawings.
Documentation: MTC / EN 10204 3.1
Heavy Hex Bolts
Product Type: Heavy Hex Bolts / Large Diameter Heavy Hex Bolts / Custom Heavy Hex Bolts
Size Range: Standard / Custom
Thread System: Metric / UNC / UNF
Thread Type: Coarse / Fine
Standard: Dimensional Standards: ISO / DIN / ASME, as applicable, or customer drawings.
Documentation: MTC / EN 10204 3.1
Stud Bolts
Product Type: Fully Threaded Studs / Double End Studs / Tap End Studs / Flange Stud Sets
Size Range: Standard / Custom
Thread System: Metric / UNC / UNF / 8UN
Thread Type: Coarse / Fine
Standard: Dimensional Standards: ISO / DIN / ASME, as applicable, or customer drawings.
Documentation: MTC / EN 10204 3.1
Nuts
Product Type: Hex Nuts / Heavy Hex Nuts / Custom Nuts
Size Range: Matched to Bolt / Stud Size
Thread System: Metric / UNC / UNF
Thread Type: Coarse / Fine
Standard: Dimensional Standards: ISO / DIN / ASME, as applicable, or customer drawings.
Documentation: MTC / EN 10204 3.1
Washers
Product Type: Flat Washers / Heavy Washers / Custom Washers
Size Range: Standard / Custom
Inner Diameter: Standard / Custom
Outer Diameter: Standard / Custom
Thickness: Standard / Custom
Standard: Dimensional Standards: ISO / DIN / ASME, as applicable, or customer drawings.
Documentation: MTC / EN 10204 3.1
Socket Head Cap Screws
Product Type: Socket Head Cap Screws / Custom Socket Screws
Size Range: Standard / Custom
Thread System: Metric / UNC / UNF
Thread Type: Coarse / Fine
Standard: Dimensional Standards: ISO / DIN / ASME, as applicable, or customer drawings.
Documentation: MTC / EN 10204 3.1
Threaded Rods
Product Type: Fully Threaded Rods / Cut-to-Length Threaded Rods
Size Range: Standard / Custom
Thread System: Metric / UNC / UNF
Thread Type: Coarse / Fine
Standard: Dimensional Standards: ISO / DIN / ASME, as applicable, or customer drawings.
Documentation: MTC / EN 10204 3.1
Custom Fasteners & Machined Components
Product Type: Custom Bolts / Special Studs / Machined Components
Tolerance: According to drawing
Manufacturing Basis: Customer Drawing
Inspection: Dimensional / PMI / Mechanical testing
Documentation: MTC / EN 10204 3.1
Need a Product Type Not Shown Here?
We also manufacture custom and project-specific fasteners according to drawings, specifications or application requirements.
Process Control
Manufacturing Excellence
A controlled six-stage production workflow supports consistent manufacturing from reviewed raw material to finished, identified and export-ready specialty-alloy fasteners.
01
Raw Material Preparation
The specified alloy grade, product form, material condition and batch identity are reviewed before cutting. Stock is prepared according to the order and selected manufacturing route.
02
Cutting & Blanking
Bars, rods or forgings are cut to the required blank size while maintaining material separation and batch identification.
03
Forging / CNC Machining
Headed fasteners are forged and machined when appropriate, while complex, low-volume or drawing-based components can be produced by precision CNC machining.
04
Thread Manufacturing
Threads are rolled or cut according to material condition, product geometry, dimensional standard and customer requirements.
05
Heat Treatment
Solution treatment, annealing, age hardening or other thermal processing is applied only when required by the alloy grade, material condition and governing specification.
06
Finishing & Packing
Finished parts are deburred, cleaned and prepared as specified, then identified and packed according to order and traceability requirements.
Quality Control
Quality Assurance & Full Traceability
Inspection and documentation are planned around the purchase specification, customer drawing and intended service. The agreed inspection scope is confirmed according to individual project requirements.
Material Verification
Material grade, heat or lot number and incoming documents are checked against the agreed order requirements before production.
Heat Number Traceability
Batch identity is maintained through production, inspection and packing so finished parts can be linked to their source material.
Dimensional Inspection
Critical dimensions, tolerances and product geometry are checked against the applicable dimensional standard or customer drawing.
Thread Inspection
Thread size, pitch and fit are verified using suitable gauges and measuring equipment. Additional profile verification can be arranged when specified.
PMI & Mechanical Testing
PMI, hardness, tensile or other testing can be performed or arranged when specified, depending on the material, test method and project requirements.
MTC / EN 10204 3.1 Documentation
MTC / EN 10204 3.1 documentation, dimensional reports, PMI reports and traceability records can be supplied when specified and applicable.
Inspection methods, sampling plans, acceptance criteria and document requirements should be confirmed before order placement.
Discuss Inspection & Documentation RequirementsIndustries Served
Applications & Industries
Our specialty-alloy fasteners support demanding projects across multiple industries. Final material selection must be based on the actual temperature, corrosion medium, mechanical load, applicable standards and required service life.
Oil & Gas
Flange bolting, valves, pressure equipment, piping systems and process units exposed to pressure, temperature or corrosive media.
Chemical Processing
Reactors, heat exchangers, scrubbers, pumps and equipment handling acids, chlorides or other aggressive process media.
Power Generation
Gas and steam turbines, boilers, furnaces, heat-treatment systems and high-temperature mechanical assemblies.
Marine & Offshore
Offshore platforms, seawater systems, marine equipment and desalination installations requiring corrosion-resistant fastening.
Aerospace
Engine, thermal and precision assemblies requiring high strength, temperature capability, low weight or controlled material performance.
Nuclear & Critical Equipment
Safety-critical bolting and engineered components requiring controlled materials, documentation and reliable long-term performance.
Not every alloy is suitable for every industry or service condition. Material suitability should be confirmed against the governing specification and actual operating environment.
Discuss Your ApplicationFrequently Asked Questions
Common questions about specialty-alloy fasteners, custom manufacturing, standards, inspection, documentation and procurement.
1. What specialty-alloy fastener products can you manufacture?
Our product range includes hex bolts, heavy hex bolts, stud bolts, nuts, washers, socket head cap screws, threaded rods and drawing-based fasteners or machined components. Availability depends on material grade, dimensions and quantity.
2. Can you manufacture non-standard parts from customer drawings?
Yes. We can review drawings for custom bolts, studs, nuts, washers, threaded parts and precision machined components. The quotation is based on material, dimensions, tolerances, heat treatment, inspection requirements and order quantity.
3. Which dimensional and thread standards can you support?
Products can be manufactured to applicable ISO, DIN, ASME and other recognized dimensional standards, or to customer drawings. Metric, UNC, UNF and other thread systems can be evaluated according to the product and specification.
4. Can you provide MTC and EN 10204 3.1 documentation?
Material test certificates and EN 10204 3.1 documentation can be supplied when specified and applicable to the ordered material and product. Certificate requirements should be confirmed before order placement.
5. Is PMI or third-party inspection available?
PMI and third-party inspection can be arranged when required. The test method, sampling plan, acceptance criteria and reporting requirements should be defined before production.
6. How do you maintain material traceability?
Heat or lot identification is maintained from incoming material through production, inspection and packing, subject to the agreed order and documentation requirements.
7. Can you supply bolts, nuts and washers as matched bolting sets?
Yes. Complete bolting sets can be supplied when requested, with thread compatibility, material selection, inspection and packaging defined for the order.
8. What are your MOQ and lead time?
MOQ and lead time depend on alloy grade, raw-material availability, product size, manufacturing route, heat treatment, testing and order quantity. Made-to-order specialty-alloy fasteners normally require a technical review before confirmation.
Request for Quotation
Custom & Standard
Duplex Stainless Steel Fasteners,
Direct From
Manufacturer.
Send us your Duplex Stainless Steel fastener specifications, standards or drawings. Our engineering team will review your requirements and provide a detailed project-specific quotation.
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EN 10204 3.1
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