Very High Mechanical Strength
Super duplex stainless steels provide high yield and tensile strength, supporting demanding bolted connections exposed to substantial mechanical loads.
Specialty Alloy Fasteners
Super Duplex Stainless Steel Fasteners Manufacturer
High-strength super duplex bolts, stud bolts and custom fasteners engineered for seawater, offshore and highly corrosive chloride environments.
Super Duplex Grade Expertise
S32750 and S32760 fasteners for severe chloride, seawater and high-load industrial applications.
Extreme Corrosion Resistance
Excellent resistance to pitting, crevice corrosion and chloride stress corrosion cracking.
Custom Manufacturing
Standard and drawing-based super duplex fasteners manufactured to project-specific dimensions and requirements.
Overview
Super Duplex Stainless Steel Fasteners for Severe Corrosion & High-Load Environments
Super duplex stainless steels are highly alloyed austenitic-ferritic stainless steels developed for applications requiring greater corrosion resistance and mechanical strength than standard duplex grades. Their high chromium, molybdenum and nitrogen content provides excellent resistance to chloride stress corrosion cracking, pitting and crevice corrosion, making super duplex fasteners particularly suitable for seawater, offshore and chemical processing applications. S32750 and S32760 are two widely used super duplex grades. Both provide very high strength and corrosion resistance, while S32760 additionally contains controlled copper and tungsten additions for specific demanding service environments.
Why Choose This Material
Why Super Duplex Stainless Steel Is Selected for Critical Fastening Applications
Super duplex stainless steel combines very high strength, chloride resistance and localized corrosion resistance for critical industrial fastening systems.
Excellent Chloride SCC Resistance
The duplex microstructure provides excellent resistance to chloride stress corrosion cracking in seawater, offshore and process environments.
Exceptional Pitting & Crevice Resistance
High chromium, molybdenum and nitrogen levels provide excellent resistance to localized corrosion in aggressive chloride-containing environments.
Grade Selection Flexibility
S32750 and S32760 provide closely related super duplex solutions with different alloying approaches for specific project and service requirements.
Super Duplex Stainless Steel Grades Available for Fasteners
S32750 and S32760 provide high-strength super duplex solutions for severe chloride, seawater and corrosion-resistant fastening applications.
Super Duplex 2507 / S32750
UNS:
S32750
EN / W.Nr.:
1.4410
ASTM A182 Forging Grade:
F53
Standards
- ASTM A276
- ASTM A479
- EN 10088-3
- ASTM A182 F53
Characteristics
- Very high mechanical strength
- Excellent chloride SCC resistance
- Excellent pitting and crevice resistance
Applications
Oil & gas, Offshore equipment, Seawater systems, Desalination
Super Duplex S32760
UNS:
S32760
EN / W.Nr.:
1.4501
ASTM A182 Forging Grade:
F55
Standards
- ASTM A276
- ASTM A479
- EN 10088-3
- ASTM A182 F55
Characteristics
- Very high mechanical strength
- Excellent localized corrosion resistance
- Copper- and tungsten-alloyed super duplex grade
Applications
Oil & gas, Offshore systems, Chemical processing, Desalination
Other Super Duplex Grades Available
Additional super duplex grades can be reviewed according to customer drawings, project specifications and service requirements.
Chemical Composition of Super Duplex Stainless Steel Grades
Compare the principal alloying elements of S32750 and S32760 and the compositional differences that influence their corrosion performance.
| GRADE | CR (%) | NI (%) | MO (%) | N (%) | C (%) | OTHER (%) |
|---|---|---|---|---|---|---|
| 2507 / S32750 | 25.0 | 7.0 | 4.0 | 0.30 | 0.030 max | Cu 0.50 max |
| S32760 | 24.0–26.0 | 6.0–8.0 | 3.0–4.0 | 0.20–0.30 | 0.030 max | W 0.50–1.00, Cu 0.50–1.00 |
Reference values are provided for general comparison only. The governing material specification and batch MTC take precedence for production and acceptance.
Mechanical Performance of Super Duplex Stainless Steel Grades
Super duplex grades provide very high proof strength together with useful ductility in the solution-annealed condition.
| GRADE / CONDITION | TENSILE STRENGTH (MPA) | 0.2% YIELD STRENGTH (MPA) | ELONGATION (%) |
|---|---|---|---|
| 2507 / S32750 — Solution Annealed | 760–930 | 550 min | 25 min |
| S32760 — Solution Annealed & Quenched | 750 min | 550 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.
Super Duplex Stainless Steel Grade Selection Guide
Both grades suit severe corrosion service; final selection should follow the required alloy specification and actual operating environment.
| Application Requirement | Recommended Grade |
|---|---|
| General super duplex applications | 2507 / S32750 |
| Aggressive chloride environments | S32750 / S32760 |
| Seawater and offshore systems | S32750 / S32760 |
| Oil & gas equipment | S32750 / S32760 |
| ASTM A182 F53 requirement | S32750 |
| ASTM A182 F55 requirement | S32760 |
| Copper / tungsten alloying specifically required | S32760 |
| Project specifies UNS S32750 | 2507 / S32750 |
| Project specifies UNS S32760 | S32760 |
Super Duplex Stainless Steel Fastener Product Range
Super duplex fasteners are available in standard and custom configurations for offshore, marine, chemical and severe corrosion applications.
Super Duplex 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
Super Duplex 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
Super Duplex 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
Super Duplex 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 / Heat No. Traceability
Super Duplex 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 / Heat No. Traceability
Super Duplex 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 / Heat No. Traceability
Super Duplex 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 / Heat No. Traceability
Custom Super Duplex Fasteners & Machined Components
Product Type: Custom Bolts / Special Studs / Threaded Parts / Machined Components
Size Range: According to Drawing
Tolerance: According to Drawing
Manufacturing Basis: Customer Drawing / Project Specification
Inspection: Dimensional / PMI / Mechanical Testing as Required
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
Super Duplex Stainless Steel Fasteners,
Direct From
Manufacturer.
Send us your Super Duplex Stainless Steel fastener specifications, standards or drawings. Our engineering team will review your requirements and provide a detailed project-specific quotation.
ISO 9001
EN 10204 3.1
Global Shipping
Get Your Quote
Fill out the form below or email us directly with your drawings.