Inconel 625 Flange Dimensions and Tolerances Explained

In the world of high-performance industrial components, precision is the difference between success and failure.

Inconel 625 flanges represent a critical solution for industries operating in extreme environments, from deep-sea drilling operations to chemical processing plants and aerospace applications. These flanges, manufactured from the nickel-chromium-molybdenum-niobium superalloy, provide exceptional corrosion resistance and maintain high strength at elevated temperatures, making them indispensable in challenging operational conditions. Understanding their dimensions and tolerances is essential for ensuring proper fit, function, and safety in critical applications.

Inconel 625 Material Composition and Properties

Inconel 625 is a nickel-chromium-molybdenum-niobium superalloy designed to maintain its properties under extreme conditions. The chemical composition of this remarkable alloy includes:

Nickel (Ni): ≥58% - provides the austenitic matrix and corrosion resistance

Chromium (Cr): 20-23% - offers oxidation resistance

Molybdenum (Mo): 8-10% - enhances strength and corrosion resistance

Niobium (Nb): 3.15-4.15% - acts as a strengthening element

Iron (Fe): ≤5% - present in limited quantities

Carbon (C): ≤0.10% - kept low to enhance corrosion resistance

This unique composition gives Inconel 625 flanges their exceptional performance characteristics, including excellent fatigue strength, resistance to chloride-ion stress-corrosion cracking, and outstanding corrosion resistance in various aggressive environments, from seawater to acidic conditions .

Standard Specifications for Inconel 625 Flanges

Inconel 625 flanges are manufactured according to established international standards to ensure consistency and reliability:

Material Specification: ASTM B564 / ASME SB564

Dimensional Standards: ANSI/ASME B16.5, ANSI B16.47 Series A & B, MSS SP44, BS4504, BS10, EN-1092, DIN

Pressure Ratings: 150#, 300#, 600#, 900#, 1500#, 2500#, PN6, PN10, PN16, PN25, PN40, PN64

Size Range: 1/2" NB to 60" NB

Dimensions and Tolerances for Inconel 625 Flanges

Common Flange Types

Inconel 625 is available in various flange types to suit different application requirements:

Bl Inconel 625 flange

long weld Inconel 625 flanges

PJ Inconel 625 flange

PL Inconel 625 flange

SO Inconel 625 flange

SW Inconel 625 flange

TH Inconel 625 flange

WN Inconel 625 Welding Flange

Dimension Tables by Pressure Rating

150# Flange Dimensions (ANSI B16.5)

300# Flange Dimensions (ANSI B16.5)

1500# RTJ Flange Dimensions (ANSI B16.5)

Note: RTJ flanges feature a groove for a ring gasket and are used in high-pressure applications .

Tolerance Standards for Inconel 625 Flanges

Dimensional Tolerances

Outside Diameter: +1/16", -0 for sizes up to 12"; +3/32", -0 for larger sizes

Thickness: ±1/16" for flanges up to 12"; ±1/8" for larger flanges

Bolt Hole Spacing: ±1/32" for bolt circle diameter

Bore Diameter: ±1/32" for sizes up to 12"; ±1/16" for larger sizes

Face Flatness: 0.015" per inch of diameter, not to exceed 0.06" total

Manufacturing Tolerances

Inconel 625 flanges are typically produced through forging processes to ensure optimal grain structure and mechanical properties. The manufacturing tolerances are strictly controlled according to ASME and ASTM specifications to guarantee proper fit-up and sealing capability in critical applications .

Application-Specific Considerations

High-Temperature Applications

Inconel 625 flanges maintain their strength at elevated temperatures, with a melting range of 1290-1350°C (2460°F) . At 982°C (1800°F), they retain excellent oxidation resistance and a tensile strength of approximately 827 MPa . This makes them suitable for:

Aerospace components

Exhaust systems

High-temperature processing equipment

Corrosion Resistance Applications

The alloy's composition provides outstanding resistance to various corrosive environments:

Chloride-induced stress corrosion cracking

Pitting and crevice corrosion in seawater and chemical processing

Acidic environments including sulfuric, phosphoric, and nitric acids

This corrosion resistance makes Inconel 625 flanges ideal for:

Chemical and petrochemical processing

Marine and offshore applications

Pollution control equipment

Pulp and paper manufacturing

Quality Assurance and Testing

Inconel 625 flanges undergo rigorous quality control procedures, including:

Chemical analysis to verify composition

Mechanical testing to ensure tensile strength, yield strength, and elongation meet specifications

Non-destructive testing such as ultrasonic examination or radiography

Dimension verification against applicable standards

Certification according to EN 10204/3.1B or similar standards

TSM TECHNOLOGY CO., LTD.: Your Trusted Partner for High-Performance Flanges

At TSM TECHNOLOGY CO., LTD., we specialize in manufacturing precision Inconel 625 flanges that meet the most demanding specifications. Our flanges are produced with strict adherence to international standards and undergo comprehensive quality control to ensure reliability in your most critical applications.

Why choose TSM TECHNOLOGY CO., LTD.:

Expertise in high-performance alloys

Comprehensive quality assurance

Custom solutions for specialized applications

Technical support throughout project lifecycle

For inquiries or to request a free sample, contact us at info@tsmnialloy.com.