ASTM A350 LF2
A350 LF2: Specifications | Grades & Standards | Product Types | Equivalent Grades | Chemical Composition | Mechanical Properties | Forged Fittings | Flanges | FAQ
ASTM A350 LF2 Low Temperature Carbon Steel Fogred Fittings & Flanges – Bushing, Cap, Cross, Swage Nipple, Weld Neck, Slip-On, Blind, Threaded & Orifice Flanges – Manufacturer & Exporter, serving USA, Germany, Italy, UAE & Middle East.
Best Export Prices: sales@midlandforgefittings.com
Midland Forge and Fittings Pvt. Ltd. is a leading manufacturer and exporter of precision low-temperature carbon steel piping components. With advanced forging and machining facilities, every forged fitting and flange meets strict dimensional, metallurgical, and mechanical standards, complying with ASTM, ASME, DIN, EN, and ISO requirements for high-pressure and high-temperature applications.
A skilled team of engineers, metallurgists, and technicians ensures precision and quality in all processes. With advanced process control, in-house testing, and heat treatment, the company delivers durable, high-strength, and corrosion-resistant fittings and flanges, serving industries like oil & gas, petrochemical, power, and marine.
ASTM A350 LF2 is a low-temperature carbon steel grade widely used for forged fittings and flanges in applications requiring toughness at sub-zero temperatures. The product range includes elbows, tees, reducers, caps, crosses, and various flanges such as weld neck, slip-on, blind, threaded, and orifice flanges.
A350 LF2 components are manufactured to ASTM A350/A350M specifications and comply with ASME B16.9, ASME B16.11, ASME B16.5, MSS-SP-58 standards, ensuring uniformity in dimensions, mechanical properties, and pressure ratings. Grade variations such as LF1, LF2, LF3, and LF2 CL1/CL2 cater to different temperature, toughness, and chemical composition requirements, enabling the selection of the most suitable grade for low-temperature pipelines, pressure vessels, and cryogenic systems.
Low-temperature carbon steel Forged Fittings Specifications
ASTM A350 LF2 Class 1 / Class 2 Flange – Grades & Standards
| Carbon Steel Grade | UNS No. | Applicable Standards | Typical Products |
|---|---|---|---|
| ASTM A350 LF2 | K02501 | ASTM A350/A350M, ASME B16.9, ASME B16.11, ASME B16.5, MSS-SP-58 | Forged Fittings, Flanges |
LTCS A350 LF2 Products
CS A350 LF1 / LF3 Threaded 90 deg Elbow Fittings - Equivalent Grades
| ASTM A350 Grade | UNS No. | EN / DIN Equivalent | JIS Equivalent | BS / UK Equivalent | GOST / Russia Equivalent |
|---|---|---|---|---|---|
| LF1 | K02500 | 1.0565 / P240GH | SF420A | 43A | 20GL |
| LF2 | K02501 | 1.0566 / P250GH | SF440A | 43C | 20GL |
| LF3 | K02502 | 1.0567 / P265GH | SF480A | 43D | 20GLL |
| LF5 | K02503 | 1.0568 / P280GH | SF500A | 43E | 22GL |
| LF6 | K02504 | 1.0569 / P295GH | SF520A | 43F | 22GLL |
| LF9 | K02505 | 1.0570 / P355GH | SF540A | 43G | 25GL |
Carbon Steel A350 LF5 / LF6 Plate Flange - Chemical Composition
| Grade | C (%) | Mn (%) | P (%) | S (%) | Si (%) | Cu (%) | Ni (%) | Cr (%) | Mo (%) |
|---|---|---|---|---|---|---|---|---|---|
| LF1 | 0.18–0.23 | 0.50–0.90 | ≤0.035 | ≤0.035 | 0.10–0.35 | ≤0.35 | ≤0.40 | ≤0.30 | ≤0.15 |
| LF2 | 0.22–0.28 | 0.60–1.00 | ≤0.035 | ≤0.035 | 0.10–0.35 | ≤0.35 | ≤0.40 | ≤0.30 | ≤0.15 |
| LF3 | 0.24–0.30 | 0.70–1.10 | ≤0.035 | ≤0.035 | 0.10–0.35 | ≤0.35 | ≤0.40 | ≤0.30 | ≤0.15 |
| LF5 | 0.26–0.32 | 0.75–1.15 | ≤0.035 | ≤0.035 | 0.10–0.35 | ≤0.35 | ≤0.40 | ≤0.30 | ≤0.15 |
| LF6 | 0.28–0.34 | 0.80–1.20 | ≤0.035 | ≤0.035 | 0.10–0.35 | ≤0.35 | ≤0.40 | ≤0.30 | ≤0.15 |
| LF9 | 0.30–0.36 | 0.85–1.25 | ≤0.035 | ≤0.035 | 0.10–0.35 | ≤0.35 | ≤0.40 | ≤0.30 | ≤0.15 |
Low-temperature A350 LF9 Fittings- Mechanical Properties
| Grade | Minimum Yield Strength (MPa) |
Minimum Tensile Strength (MPa) |
Elongation (%) |
Impact Toughness (J at -46°C) |
Hardness (HB) |
|---|---|---|---|---|---|
| LF1 | 205 | 415–535 | 22 | 27 | 187 |
| LF2 | 250 | 485–655 | 22 | 27 | 187 |
| LF3 | 275 | 515–690 | 21 | 27 | 187 |
| LF5 | 295 | 530–710 | 21 | 27 | 187 |
| LF6 | 315 | 550–725 | 20 | 27 | 187 |
| LF9 | 335 | 565–745 | 20 | 27 | 187 |
Carbon Steel ASTM A350 LF2 Flanges – ANSI / ASME Standards
A350 LF2 Forged Components: Threaded & Socket Weld Fittings
What are the different grades under ASTM A350?
LF1: This is the basic grade with relatively lower carbon content, providing adequate toughness at moderately low temperatures. It is generally used for applications where extreme cold service is not critical.
LF2: The most commonly used grade in the series, LF2, is engineered for general low-temperature applications. It offers excellent toughness and ductility down to -46°C and is widely employed in pressure vessels, cryogenic piping, and industrial pipelines.
LF3: LF3 provides higher tensile and yield strengths compared to LF1 and LF2 while maintaining toughness. It is preferred for heavier-duty low-temperature applications, including large-diameter piping and higher-pressure systems.
LF5 and LF6: These grades are intended for more demanding low-temperature conditions, offering enhanced mechanical performance and notch toughness. LF5 and LF6 are used in specialized piping systems, pressure vessels, and offshore applications where structural integrity under cold conditions is critical.
LF9: The highest grade in the A350 series, LF9 combines maximum tensile strength with excellent low-temperature impact resistance, suitable for extreme cryogenic service or ultra-low temperature environments.
Each grade can also have class designations, such as Class 1 or Class 2, which further define the toughness and temperature rating of the material. Class 1 generally indicates standard low-temperature performance, while Class 2 may include enhanced toughness or additional testing requirements. Selecting the appropriate grade and class ensures that piping components, fittings, and flanges maintain structural integrity, safety, and reliability under specific low-temperature and high-pressure service conditions.
Can ASTM A350 LF2 be welded and machined easily?
Yes, LF2 is highly weldable using SMAW, GTAW, GMAW, and SAW processes.
Preheating may be recommended for thick sections to prevent cracking.
Machining is generally straightforward due to balanced carbon content and low hardness, enabling fabrication of custom components.
How does ASTM A350 LF2 perform in low-temperature service?
LF2 is normalized or normalized + tempered to refine the grain structure, improving impact toughness at sub-zero temperatures.
Charpy V-notch testing at -46°C is performed to confirm notch toughness, ensuring that the material will resist brittle fracture under extreme cold.
Its low carbon and controlled alloying elements enhance ductility, weldability, and reliability in cryogenic and low-temperature environments.