Kanakratna Steelage Private Limited

Introduction

In critical industries like offshore oil & gas, desalination, chemical processing, and marine engineering, equipment is constantly exposed to chloride-rich, acidic, and high-pressure environments. One of the most overlooked yet vital components in these systems is the nut, which secures bolts and ensures the integrity of joints, flanges, pressure vessels, and pipelines.

Standard stainless steel nuts such as 304 or 316L often fail under such extreme conditions due to pitting, crevice corrosion, and stress corrosion cracking (SCC). To overcome these limitations, engineers rely on Super Duplex Stainless Steel Nuts, manufactured primarily from UNS S32750 (2507) and UNS S32760.

These nuts are engineered for exceptional corrosion resistance and mechanical strength, making them suitable for subsea operations, desalination plants, petrochemical refineries, and renewable energy projects.

Chemical CompositionUNS S32750 (EN 1.4410, ASTM A182 F53)

 

UNS S32760 (EN 1.4501, ASTM A182 F55) Physical Properties Mechanical Properties Testing & Quality Control

• Mechanical Tests: Tensile, yield, hardness, and impact.

• Corrosion Tests: ASTM G48 (pitting test).

• Ferrite Testing: Confirms 40–60% ferrite phase.

• Non-Destructive Tests (NDT): Ultrasonic, radiography, dye penetrant.

• Dimensional Inspections: Thread gauge, torque check.

• Positive Material Identification (PMI): Ensures correct alloy grade.

Additional Information:

• Production Capacity: IN TONS
• Delivery Time: READY STOCK
• Packaging Details: The packaging of the product is done using an effective method of packaging. It all includes- • Shrink-wrapping • Bubble wrapping • Carton boxes • Wooden crates/pallets/boxes

Introduction

In industries such as oil & gas, offshore platforms, desalination, chemical processing, and marine engineering, fasteners like bolts are exposed to some of the harshest environments on Earth. Conventional stainless steels such as 304 and 316L often fail due to chloride-induced pitting, crevice corrosion, or stress corrosion cracking (SCC).

To meet these demanding conditions, engineers increasingly specify Super Duplex Stainless Steel Bolts, manufactured primarily from UNS S32750 (2507) and UNS S32760. These alloys belong to the super duplex family, combining the toughness and ductility of austenitic stainless steels with the high strength and stress corrosion cracking resistance of ferritic stainless steels.

Super Duplex Bolts provide:

• Twice the strength of 300-series stainless steels.

• Outstanding resistance to localized corrosion in seawater and chemical environments.

• Cost savings by allowing thinner cross-sections due to high yield strength.

These properties make them the fastener of choice for subsea equipment, pressure vessels, desalination plants, and offshore oil rigs.

Chemical CompositionUNS S32750 (EN 1.4410, ASTM A182 F53) UNS S32760 (EN 1.4501, ASTM A182 F55) Physical Properties Mechanical Properties Testing & Quality Control

• Chemical Analysis – OES, Spectro analysis.

• Mechanical Testing – Tensile, hardness, impact tests.

• Corrosion Testing – ASTM G48 pitting test.

• NDT: Ultrasonic, radiography, dye penetrant.

• Dimensional Checks: Thread gauge, tolerance verification.

• Ferrite Testing: Ensures 40–60% ferrite balance.

Additional Information:

• Production Capacity: 50 TONS
• Delivery Time: READY STOCK
• Packaging Details: The packaging of the product is done using an effective method of packaging. It all includes- • Shrink-wrapping • Bubble wrapping • Carton boxes • Wooden crates/pallets/boxes

Introduction

Super Duplex Steel Bars are advanced stainless steel products designed for use in highly demanding and corrosive environments. They belong to the duplex stainless steel family, which means they have a two-phase microstructure consisting of approximately equal amounts of austenite and ferrite.

Super Duplex steels offer a unique combination of high strength, toughness, and exceptional corrosion resistance, especially in chloride-containing and acidic environments. Compared to standard duplex stainless steels, Super Duplex grades contain higher levels of chromium, molybdenum, and nitrogen, which give them enhanced resistance to pitting, crevice corrosion, and stress corrosion cracking.

Chemical Composition of Super Duplex Bars

The chemical composition of Super Duplex Stainless Steel varies slightly across different grades, but the most common one is UNS S32750 (2507).

 

 Mechanical Properties  Physical Properties Quality Testing

• Mechanical Testing (Tensile, hardness, impact)

• Chemical Composition (Spectrometer analysis)

• Intergranular Corrosion Test (IGC)

• Pitting Resistance Test

• Non-Destructive Testing (UT, RT, MPI)

• Third-Party Inspections (Lloyd’s, TUV, BV, SGS)

Additional Information:

• Production Capacity: IN TONS
• Delivery Time: READY STOCK
• Packaging Details: The packaging of the product is done using an effective method of packaging. It all includes- • Shrink-wrapping • Bubble wrapping • Carton boxes • Wooden crates/pallets/boxes

Introduction

Super Duplex 2507 Round Bar is a high-performance engineering product manufactured from Super Duplex stainless steel UNS S32750 / 1.4410, commonly known as 2507 alloy. It belongs to the family of super duplex stainless steels, which are designed to deliver exceptional strength, toughness, and resistance to aggressive corrosion environments.

Super Duplex 2507 combines the ferritic and austenitic structures, giving it twice the strength of standard austenitic stainless steels like 304 and 316. The 2507 grade was specifically developed for demanding applications such as offshore oil & gas platforms, seawater desalination plants, chemical processing units, and marine engineering, where both mechanical performance and corrosion resistance are crucial.

Chemical Composition of Super Duplex 2507

Super Duplex 2507 Round Bars derive their superior characteristics from a carefully balanced chemical composition.

Typical Composition (% by weight):

 

Mechanical Properties of Super Duplex 2507 Round Bar

Super Duplex 2507 round bars exhibit twice the mechanical strength of 300-series stainless steels, making them ideal for high-stress applications.

Physical Properties

• Density: 7.8 g/cm³

• Melting Range: 1350 – 1400 °C

• Thermal Conductivity: 14 W/m·K

• Electrical Resistivity: 8.5 × 10⁻⁷ Ω·m

• Elastic Modulus: ~200 GPa

• Thermal Expansion (20–100 °C): 13 µm/m·K

 Testing and Quality Assurance

To ensure reliability, Super Duplex 2507 round bars undergo stringent testing:

• Chemical Analysis (Spectroscopy)

• Mechanical Testing (Tensile, Yield, Impact, Hardness)

• Corrosion Testing (ASTM G48 Pitting Test)

• Non-Destructive Testing (Ultrasonic, Eddy Current, Radiography)

• Hydrostatic Testing (for pressure applications)

• Surface & Dimensional Inspection

 Heat Treatment and Machinability

• Heat Treatment: Solution annealed at 1020–1100 °C, water quenched.

• Machinability: More difficult than standard stainless steels but achievable with high-speed carbide tools.

• Weldability: Good, provided proper filler materials (ER2594, E2594) are used.

Additional Information:

• Production Capacity: IN TON
• Delivery Time: 7-30days, according to the quantity
• Packaging Details: The packaging of the product is done using an effective method of packaging. It all includes- • Shrink-wrapping • Bubble wrapping • Carton boxes • Wooden crates/pallets/boxes

Introduction

Super Duplex 2507 Round Bar (UNS S32750 / 1.4410) is a high-performance stainless steel bar designed to withstand the most aggressive industrial environments. It belongs to the super duplex stainless steel family, which combines the best features of austenitic stainless steels (like 316L, 904L) and ferritic stainless steels, offering high strength, excellent corrosion resistance, and cost-effectiveness.

Unlike standard duplex grades (such as 2205), Super Duplex 2507 offers superior resistance to chloride-induced corrosion, stress corrosion cracking (SCC), and erosion, making it the material of choice for marine, oil & gas, desalination, and chemical industries.

 Chemical Composition of Super Duplex 2507 Round Bar

The excellent corrosion resistance and mechanical strength of 2507 come from its balanced dual-phase microstructure and carefully designed chemical composition:

 

Mechanical Properties of Super Duplex 2507 Round Bar

Super Duplex 2507 offers twice the strength of conventional austenitic stainless steels.

Physical Properties

• Density: 7.8 g/cm³

• Melting Range: 1350 – 1400 °C

• Thermal Conductivity (20°C): 14.5 W/m·K (higher than austenitic steels)

• Electrical Resistivity (20°C): 0.80 µΩ·m

• Elastic Modulus: ~200 GPa

• Thermal Expansion Coefficient (20–100 °C): 13 µm/m·K

This means Super Duplex 2507 has better heat transfer efficiency and lower thermal expansion compared to austenitic steels, reducing risk of thermal fatigue.

Testing & Quality Control

To ensure reliability, 2507 round bars undergo:

 

• Chemical Composition Testing (Spectroscopy)

• Mechanical Testing (Tensile, Hardness, Impact)

• Corrosion Testing (ASTM G48 – Pitting Resistance Test)

• NDT (Ultrasonic, Eddy Current, Radiography)

• Microstructure Examination – ferrite-austenite balance

• Dimensional Accuracy & Surface Finish Check

 Heat Treatment, Welding, and Machining

• Heat Treatment: Solution annealed at 1020–1120 °C, water quenched.

• Welding: Weldable using matching filler metals (ER2594, E2594, or Alloy 625). Preheating not required.

• Machinability: Lower than austenitic steels due to high strength. Requires rigid tooling, slower speeds, and carbide inserts.

Additional Information:

• Production Capacity: IN TONS
• Delivery Time: READY STOCK
• Packaging Details: The packaging of the product is done using an effective method of packaging. It all includes- • Shrink-wrapping • Bubble wrapping • Carton boxes • Wooden crates/pallets/boxes

 Introduction

Fasteners are among the most critical components in engineering and construction, holding together assemblies in chemical plants, refineries, desalination facilities, offshore rigs, and aerospace structures. When these fasteners must withstand aggressive corrosion, high temperatures, and extreme mechanical loads, conventional stainless steels and nickel alloys often fail. This is where Hastelloy Nut Bolts come into play.

Hastelloy is the trademark name for a family of nickel-molybdenum, nickel-iron-chromium, and nickel-chromium-molybdenum alloys, each designed for specific corrosion-resistant applications. Manufactured into nuts, bolts, studs, and other fasteners, Hastelloy fasteners are known for exceptional resistance to strong oxidizers, reducing agents, seawater, and acid environments.

Hastelloy Nut Bolts are widely used in chemical processing equipment, pollution control systems, marine engineering, and high-temperature aerospace applications.

Chemical Composition (Typical for C276 – Widely Used for Nut Bolts)

 

Mechanical Properties (Typical for Hastelloy C276 Nut Bolt) Physical Properties  Testing & Quality Assurance

• PMI (Positive Material Identification) – ensures correct alloy.

• Tensile Testing – for mechanical strength.

• Hardness Testing – Rockwell/Brinell.

• Corrosion Testing – per ASTM G28, ASTM G48.

• Ultrasonic Testing – detects internal flaws.

• Third-Party Inspection (TPI) – DNV, SGS, BV certifications.

Packaging & Supply

• Supplied as hex bolts, stud bolts, socket cap screws, nuts.

• Sizes: M6 to M100 (¼” to 4”).

• Threads: UNC, UNF, Metric, BSW.

• Packaging: Export-worthy wooden boxes, poly bags, coated to prevent rust.

Additional Information:

• Production Capacity: IN TONS
• Delivery Time: READY STOCK
• Packaging Details: The packaging of the product is done using an effective method of packaging. It all includes- • Shrink-wrapping • Bubble wrapping • Carton boxes • Wooden crates/pallets/boxes