ASTM A694 F46
ASTM A694 F46 Flanges & Fittings
ASTM A694 Grade F46 is a high-strength carbon steel forging material engineered for use in high-pressure transmission systems. This grade is widely used in oil & gas pipelines, petrochemical industries, cross-country transmission lines, and offshore platforms where superior strength, toughness, and reliability are essential.
F46 is part of the A694 standard which includes forged carbon steel flanges, fittings, valves, and components designed to handle extreme pressure and demanding operating conditions. With enhanced mechanical strength and excellent impact resistance, ASTM A694 F46 is the preferred material for pipeline flanges and critical pressure vessel components.
Key Features
High tensile & yield strength
Excellent performance under high pressure
Good toughness & fatigue resistance
Suitable for low-temperature operations
Good weldability & machinability
Designed for critical pipeline applications
Specification
| Standard | ASTM A694 |
|---|---|
| Grade | F46 |
| Product | Forged Carbon Steel Flanges, Fittings, Components |
| Condition | Normalized / Quenched & Tempered |
| Application | High-pressure pipeline systems |
Equivalent Grades
| Standard | Grade |
|---|---|
| ASTM | A694 F46 |
| ASME | SA694 F46 |
| EN | — |
| DIN | — |
| API | API 6A (Comparable Service Class) |
Available Sizes
| Product | Size Range |
|---|---|
| Flanges | ½” – 60″ NB |
| Forged Fittings | ½” – 4″ NB |
| Forged Bars / Rings / Blocks | Custom Sizes |
| Custom Machined Components | As per drawing |
Chemical Composition
| Element | % (Max/Range) |
|---|---|
| Carbon (C) | 0.30 Max |
| Manganese (Mn) | 0.60 – 1.35 |
| Phosphorus (P) | 0.025 Max |
| Sulfur (S) | 0.025 Max |
| Silicon (Si) | 0.15 – 0.40 |
| Vanadium (V) | 0.08 Max |
| Niobium (Nb) | 0.05 Max |
| Titanium (Ti) | 0.04 Max |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | 485 MPa Min |
| Yield Strength | 320 MPa Min |
| Elongation | 22% Min |
| Hardness | 197 HB Max |
| Impact Test | Required for pipeline service |
Physical Properties
| Property | Value |
|---|---|
| Density | 7.85 g/cm³ |
| Modulus of Elasticity | 190 – 210 GPa |
| Thermal Conductivity | ~45 W/m-K |
| Melting Point | 1425 – 1540°C |
Type of ASTM A694 F46 Flanges
Corrosion Resistance
Good resistance to atmospheric and mild corrosive environments
Protective coatings recommended for marine, sour gas, or chemical exposure
Compatible with cathodic protection systems in pipelines
Heat Resistance
Stable mechanical properties up to ~450°C
Designed for moderate-temperature high-pressure applications
Not recommended for continuous high-temperature exposure above limits
Heat Treatment
Normalizing
Quenching & Tempering
Stress Relieving (if required)
Heat treatment enhances toughness and grain refinement.
Welding
Good weldability with standard procedures
Pre-heating recommended for thicker sections
PWHT suggested depending on weld thickness & service condition
Low-hydrogen electrodes recommended
Fabrication
Excellent forgeability and machinability
Suitable for turning, drilling, threading & shaping
Can be manufactured to OEM drawings and pipeline standards
Applications
Crude oil & natural gas pipeline networks
Petrochemical & LNG plants
Offshore drilling & subsea equipment
High-pressure valves, flanges, tees & elbows
Compressor & pumping stations
refinery and transmission systems