ASTM A694 F48
ASTM A694 F48 Flanges & Fittings
ASTM A694 F48 is a high-strength carbon steel forging grade designed for severe high-pressure pipeline applications. F48 delivers exceptional strength, impact toughness, and reliability under demanding operating environments such as oil & gas transmission lines, refinery systems, LNG projects, and offshore energy facilities.
This material is specially engineered to withstand extreme pressure fluctuations, temperature variation, and pipeline stress, making it one of the preferred options for critical pipeline components including flanges, forged fittings, and valve parts.
Key Features
High tensile & yield strength for pressure-critical systems
Excellent impact and fatigue resistance
Suitable for low-temperature pipeline operations
Uniform grain structure and enhanced toughness
Reliable weldability and forgeability
Ideal for cross-country & offshore pipeline projects
Specification
| Standard | ASTM A694 |
|---|---|
| Grade | F48 |
| Product | Forged Flanges, Fittings, Pipeline Components |
| Condition | Normalized / Quenched & Tempered |
| Application | High-Pressure Oil & Gas Transmission Systems |
Equivalent Grades
| Standard | Grade |
|---|---|
| ASTM | A694 F48 |
| ASME | SA694 F48 |
| EN | — (No direct equivalent) |
| DIN | — |
| API | API 6A (Comparable Class) |
Available Sizes
| Product | Size Range |
|---|---|
| Flanges | ½” – 60″ NB |
| Forged Fittings | ½” – 4″ NB |
| Rings, Bars, Billets | Custom Dimensions |
| Machined Components | As per Drawing |
Chemical Composition
| Element | % |
|---|---|
| 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 |
| Chromium & Nickel (Total) | ≤ 1.00 Max Combined |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | 515 MPa Min |
| Yield Strength | 345 MPa Min |
| Elongation | 22% Min |
| Hardness | 197 HB Max |
| Charpy Impact Test | Required |
Physical Properties
| Property | Value |
|---|---|
| Density | 7.85 g/cm³ |
| Elastic Modulus | 190 – 210 GPa |
| Thermal Conductivity | ~45 W/m-K |
| Melting Range | 1425 – 1540°C |
Type of ASTM A694 F48 Flanges
Corrosion Resistance
Good resistance to general atmospheric corrosion
Suitable for sweet (non-sour) service pipeline media
Coating or cladding recommended in corrosive offshore or sour gas environments
Heat Resistance
Performs reliably up to ~450°C (service-dependent)
Maintains strength under fluctuating temperature conditions
Not recommended for extended high-temperature creep service
Heat Treatment
Normalizing
Quenching & Tempering
Stress-Relieving as required
Heat treatment enhances microstructure and toughness essential for pipeline duty.
Welding
Good weldability using low-hydrogen welding procedures
Pre-heating recommended for heavy-sections
Post-Weld Heat Treatment may be needed depending on service & thickness
Fabrication
Excellent forgeability & machinability
CNC/precision machining possible
Supplied as per project drawings and pipeline codes
Applications
Cross-country crude oil & natural gas pipelines
Offshore platforms & subsea pipeline systems
LNG terminals & gas processing plants
Petrochemical & Refinery units
Pipeline valves, tees, flanges & fittings
Compressor & pump station components