Duplex 2507 Stainless Steel Fasteners

Duplex 2507 stainless steel fasteners are manufactured from UNS S32750 super duplex stainless steel, combining an austenitic-ferritic microstructure with high mechanical strength and resistance to localized corrosion.

UNS S32750 is commonly known as 2507 Super Duplex Stainless Steel. It contains chromium, molybdenum and nitrogen as major alloying elements, providing a material system designed for demanding corrosive environments.

2507 fasteners are used for bolting connections in equipment and piping systems where conventional stainless steel fasteners may not provide the required combination of mechanical strength and corrosion resistance.

Typical applications include offshore equipment, marine systems, seawater handling equipment, chemical processing equipment, oil and gas facilities, heat exchangers, pressure vessels and industrial piping systems.

Fasteners can be manufactured according to customer drawings, dimensional standards and applicable material specifications.

Product Specifications

Material Grade: UNS S32750

UNS S32750 is a 25Cr super duplex stainless steel grade containing chromium, molybdenum and nitrogen.

Its alloy design provides a combination of:

• High chromium content
• Molybdenum addition
• Nitrogen addition
• High mechanical strength
• Resistance to localized corrosion
• Duplex austenitic-ferritic microstructure

For fastener applications, the final material condition and mechanical requirements should be specified according to the applicable fastener standard and purchase order.

Chemical Composition

For UNS S32750, a typical ASTM A182 F53 / equivalent material chemistry can be presented as follows:

Note: The exact chemical composition should be verified against the material standard specified for the fastener, such as ASTM A182, ASTM A479, ASTM F60/F61 or the customer's project specification.

Mechanical Properties

Mechanical requirements depend on the selected fastener standard, product form, diameter and heat-treatment condition.

For example, when 2507 is supplied as ASTM A182 F53 forgings, the applicable mechanical requirements should be taken directly from the specified ASTM/ASME material standard.

For a finished fastener, the purchase specification should clearly define:

Do not use one generic mechanical-property table for every 2507 fastener, because requirements vary according to the applicable fastener standard and product form.

Available Fastener Types

2507 Hex Bolts

Hex head bolts are suitable for general bolted connections in industrial equipment and piping systems.

Available dimensions can be manufactured according to ANSI, ASME, DIN, ISO or customer drawings.

2507 Heavy Hex Bolts

Heavy hex bolts provide a larger head and bearing surface and are commonly specified for structural and pressure-equipment bolting.

2507 Stud Bolts

2507 stud bolts can be supplied with full-thread or reduced-thread configurations depending on the application.

Typical applications include:

• Flange connections
• Pressure vessels
• Heat exchangers
• Piping systems
• Valves
• Offshore equipment

2507 Nuts

Matching 2507 nuts can be supplied with the required thread dimensions and surface condition.

Common configurations include:

• Hex nuts
• Heavy hex nuts
• Custom nuts

2507 Washers

Super duplex 2507 washers can be supplied to match the fastener material and connection design.

Certificates and Documentation

The following documents can be provided according to project requirements:

• Material Test Certificate
• EN 10204 3.1 Certificate
• EN 10204 3.2 Certificate
• Chemical Analysis Report
• Mechanical Test Report
• PMI Report
• Dimensional Inspection Report
• Hardness Test Report
• Heat Treatment Record
• Third-Party Inspection Report
• Certificate of Conformance

Why Choose 2507 Super Duplex Fasteners?

2507 fasteners are selected when the application requires a combination of high mechanical strength and corrosion resistance from a super duplex stainless steel material.

Key material characteristics include:

• UNS S32750 material
• Approximately 25% chromium
• Molybdenum alloying
• Nitrogen alloying
• Duplex austenitic-ferritic structure
• High strength compared with many conventional austenitic stainless steels
• Suitable for selected marine, offshore and chemical applications

Material selection should always consider operating temperature, chloride concentration, stress level, fabrication requirements and compatibility with mating components.

Packaging

2507 stainless steel fasteners can be supplied with export packaging according to product size and transportation requirements.

Typical packaging includes:

• PE bags
• Plastic boxes
• Cartons
• Wooden cases
• Pallets
• Size identification labels
• Heat number identification
• Batch identification

Different fastener sizes can be separately packed and clearly labeled to simplify receiving and installation.

2507 Fastener Custom Attributes