China Duplex Steel Fasteners Manufacturers Factory - Duplex Steel Fasteners for Sale

Your Professional Duplex Steel Fasteners Supplier

Henan Shuangzhong Intelligent Technology Co., Ltd., an expert in precision manufacturing and pipeline system solutions, was founded in 1999. We are a professional manufacturer specializing in precision machining customization, pipeline equipment and pipe fittings customization, as well as the manufacturing and processing of rubber hoses.

Duplex Stainless Steel Bolts
Customizable fastener types: bolts, nuts, screws, washers, rivets, pins, clamps, etc.. Product name: Duplex Stainless Steel Bolts. Material model: Super duplex stainless steel (S31803,
Duplex Steel Threaded Rod
Product Name:Duplex Steel Threaded Rod. Customizable fastener types: bolts, nuts, screws, washers, rivets, pins, clamps, etc.. Material Model: Duplex Stainless Steel (S31803, corresponding to grade
Super Duplex Stud Bolt
Product Name:Super Duplex Stud Bolt. Customizable fastener types: bolts, nuts, screws, washers, rivets, pins, clamps, etc.. Fastener type: Fully threaded stud (completely threaded at both ends, no
Super Duplex Steel Threaded Rod
Product name：Super Duplex Steel Threaded Rod. Fastener type: Super Duplex steel S32750 threaded rod (fully threaded throughout the length, no head, suitable for long-distance rigid connections, used
DIN933 S32750 Super Duplex Bolts
Product Name:DIN933 S32750 Super Duplex Bolts. Customizable fastener types: bolts, nuts, screws, washers, rivets, pins, clamps, etc.. Material model: Super duplex stainless steel S32750

Why choose us

One-Stop Customized Solutions

We are committed to providing customers with one-stop customized solutions — from design support and precision manufacturing to quality assurance — to meet the diverse needs of various industries for high-performance, high-precision, and high-reliability industrial components.

Certification

We ensure quality through comprehensive system certifications: the company has passed the ISO 9001:2015 quality management system certification and the American Petroleum Institute (API) quality certification system.

Sales Market

Our products have been successfully exported to many countries and regions around the world, including the United States, Canada, Germany, India, Malaysia, Pakistan, the United Arab Emirates, Egypt, and the Middle East. We have earned the trust and praise of overseas customers.

On-Site Quality Supervision

We dispatch professional quality inspection teams to supervise the production of steel pipe fittings and rubber hoses. From raw material entry to the shipment of finished products, we maintain strict quality control throughout the process and accommodate special customer requirements, such as product identification and packaging methods.

Duplex Steel Fasteners

Duplex Steel Fasteners are specialized fasteners made from duplex stainless steel, a unique alloy that blends the best properties of both ferritic and austenitic stainless steels. Known for their affordability, durability, and superior corrosion resistance, these fasteners are highly versatile and are often used in harsh environments where traditional fasteners may fail. The high chromium content in duplex steel, along with a moderate amount of nickel, gives these fasteners excellent corrosion resistance, particularly against localized issues such as crevice and pitting corrosion, as well as stress corrosion cracking. Because of these characteristics, Duplex Steel Fasteners are favored for applications that require enhanced performance and longevity, making them a better choice than standard fasteners in many industrial settings.

Material Properties

Property	Details
Material	Super Duplex Stainless Steel S31803 (UNS S31803; equivalent to 2205, DIN 1.4462)
Chemical Composition	Cr: 21.0-23.0%, Ni: 4.5-6.5%, Mo: 2.5-3.5%, N: 0.08-0.20%, C: ≤0.03%, Mn: ≤2.0%, Si: ≤1.0%, P: ≤0.03%, S: ≤0.02%
Mechanical Properties	Tensile Strength: ≥690 MPa Yield Strength: ≥450 MPa Hardness: ≤290 HB (Brinell); ≤31 HRC (Rockwell) Elongation: ≥25%
Corrosion Resistance	Excellent resistance to pitting, crevice corrosion, and stress corrosion cracking (SCC) in chloride-rich environments (e.g., seawater, brines). Superior to 316/316Ti in harsh chemicals.
Temperature Range	Continuous service: -50°C to 250°C (limited by ductility at high temperatures); ideal for subsea and offshore environments.
Magnetic Property	Magnetic (due to duplex microstructure: austenite + ferrite)

Dimensional Specifications (Metric & Imperial)

Metric Size (M)	Thread Pitch (mm)	Hex Head Width (mm)	Hex Head Height (mm)	Length Range (mm)	Imperial Equivalent	Thread Type (Imperial)
M6	1.0	10.0	5.2	12-200	3/16"	UNC (3/16"-24), UNF (3/16"-32)
M8	1.25	13.0	6.8	16-300	5/16"	UNC (5/16"-18), UNF (5/16"-24)
M10	1.5	16.0	8.4	20-400	3/8"	UNC (3/8"-16), UNF (3/8"-24)
M12	1.75	18.0	10.8	25-500	1/2"	UNC (1/2"-13), UNF (1/2"-20)
M16	2.0	24.0	14.8	30-600	5/8"	UNC (5/8"-11), UNF (5/8"-18)

Standards & Applications

Standard Compliance	Key Applications
ASTM A193 B8S, ISO 4017, DIN 933	Offshore oil and gas platforms (subsea pipelines, wellheads) Desalination plants (reverse osmosis systems) Chemical processing (acids, chlorides, and corrosive slurries) Marine engineering (ship hulls, propeller shafts) Pulp and paper industry (bleaching systems with chlorine compounds)

Key Advantages Over Other Grades

Feature	S31803 (2205)	316Ti	304
Strength	High (yield strength 2× that of 316Ti)	Moderate	Lower
Chloride Resistance	Excellent (resists seawater/SCC)	Good (but limited in high chloride levels)	Poor
Weldability	Good (requires controlled heat input to avoid ferrite/austenite imbalance)	Excellent	Good
Cost	Higher (premium for duplex microstructure)	Moderate	Lower

Benefits of Duplex Steel Fasteners

In addition to their exceptional strength and corrosion resistance, duplex steel fasteners also offer excellent weldability and formability, making them easy to work with and ideal for a wide range of applications. They are commonly used in industries such as oil and gas, chemical processing, and marine engineering, where they are exposed to harsh environments and high levels of stress.

One of the key advantages of duplex steel fasteners is their ability to maintain their strength and corrosion resistance even at high temperatures. This makes them an ideal choice for applications that require high temperature resistance, such as in power generation and aerospace industries.

Duplex steel fasteners are available in a wide range of sizes and shapes, including bolts, screws, nuts, and washers. They are also available in a variety of finishes, including polished, brushed, and coated, to suit different applications and aesthetic preferences.

Common Duplex Grades for Bolts

1.4462 (UNS S32205 / EN 1.4462 / F51)

Standard duplex for general corrosive environments.

1.4410 (UNS S32750 / EN 1.4410 / F53)

Super duplex for extreme conditions (e.g., offshore, chemical plants).

1.4362 (UNS S32304 / EN 1.4362 / F40)

Lean duplex (lower nickel/molybdenum, good for cost savings).

Applications of Duplex Steel Fasteners

Oil and Gas Industry

Duplex steel fasteners are extensively used in offshore oil rigs, subsea equipment, pipelines, and petrochemical plants due to their exceptional resistance to corrosive environments and high-pressure conditions.

Chemical Processing

These fasteners find application in chemical processing plants where resistance to harsh chemicals and high temperatures is crucial for maintaining structural integrity.

Power Generation

Duplex steel fasteners are widely employed in power plants, including nuclear, thermal, and renewable energy facilities, offering excellent resistance to corrosion and elevated temperatures.

Desalination Plants

With their outstanding resistance to saltwater corrosion, duplex steel fasteners are an ideal choice for desalination plants and other marine applications.

Our Certificate

FAQ

Q: Why choose us?

A: To provide our customers with first-class services in the supply of quality fasteners minimizing costs.

Q: How is quality ensured?

A: All our processes strictly adhere to ISO9001:2008 procedures. We have strict quality control from producing to delivery.Our company had strong technology support, We have cultivated a group of managers who are familiar with product quality , good at modern concept of management.

Q: Can You Strictly Follow The Tolerance on The Drawing And Meet The High Precision?

A: Yes, we can, we can provide high precision parts and make the parts as your drawing.

Q: How should I order and make payment?

A: By T/T, for samples 100% with the order; for production, 30% paid for deposit by T/T before production arrangement, the balance to be paid before shipment.

Q: What's your Delivery Time?

A: Standard parts: 7-15days
Non-standard parts: 15-25days
We will make the delivery as soon as possible with the guarantee quality.

Q: How to Custom-made (OEM/ODM)

A: If you have a new product drawing or a sample, please send to us, and we can custom-made the hardware as your required. We will also provide our professional advices of the products to make the design to be more realized & maximize the performance.

Q: Which mode of transport would be better?

A: In general, the production are heavy, we advice to make delivery by sea, Also we respect your views of other transportation as well.

As one of the leading duplex steel fasteners manufacturers in China, we warmly welcome you to buy high quality duplex steel fasteners for sale here from our factory. Good service and reasonable price are available.