ASTM A350 LF2 Low Temperature Carbon Steel Flanges Manufacturer & Supplier
Metinox Overseas is the manufacturer and supplier of the ASTM A350 LF 2 Carbon Steel Flanges, a special designed flange with low temperature service application with high notch toughness and impact resistance. Our ASME SA350 LF2 Class 1 Flanges are made out of high-end carbon steel having controlled chemical composition of low carbon (max 0.26%), manganese (0.60-1.35%), and silicon (0.13-0.45%) with a minimum tensile strength of 485 MPa and yield strength of 240 MPa. These are A350 LF2 Carbon Steel Flanges that are designed with specifications to cold and sub-zero temperature such as -46-C (-50-F) Class 1 and -18-C (0-F) Class 2, which is most suitable to use in LNG terminals, cryogenic storage, Arctic pipeline systems, and refrigeration plants.
The false process of forging and compulsory impact testing with the Charpy V-notch test has guaranteed the high level of low temperature toughness and structural integrity on the body of the flange. Our ASTM A350 LF2 Weld Neck Flanges, Slip-On Flanges, Blind Flanges, Socket Weld Flanges are made fully to ANSI/ASME B16.5 (1/2 to 24 inch NB) and ASME B16.47 Series A (26 to 60 inch NB) dimensional standards, in full pressure classes of 150pound to 2500 pound. Every flange is heavily heat treated, to the desired impact toughness, either by normalizing, normalizing and tempering or quenching and tempering, then impact test at predetermined temperatures is required and finally, quality test including dimensional inspection, PMI verification, as well as ultrasonic inspection as required by ASTM A961.
Table of Contents
- ASTM A350 LF2 Flanges Technical Specifications
- ASTM A350 LF2 Equivalent Grades
- ASTM A350 LF2 Chemical Composition
- Mechanical Properties of ASTM A350 LF2 Flanges
- ASTM A350 LF2 Flange Dimensions & Pressure Rating Chart
- Types of ASTM A350 LF2 Flanges Available
- Standard Flange Sizes & Weight Chart
- Is ASTM A350 LF2 Good Quality for Low-Temperature Applications?
- Heat Treatment & Impact Testing Requirements
- ASTM A350 LF2 Carbon Steel Flanges Price List 2026
- Applications of ASTM A350 LF2 Flanges in Industry
- Why Choose ASTM A350 LF2 Flanges from Metinox Overseas?
- ASTM A350 LF2 Flange Delivery Time & CIF Pricing by Country
- Other Types of Carbon Steel A350 LF2 Flanges
- Popular Locations Where We Supply ASTM A350 LF2 Flanges
- Frequently Asked Questions (FAQ)
ASTM A350 LF2 Flanges Technical Specifications
| Feature | Details |
| Specifications | ASTM A350 / ASME SA350 / MSS SP-44 |
| Dimensional Standards | ANSI/ASME B16.5, B16.47 Series A & B, B16.48, API 605, MSS SP-44 |
| Size Range | 1/2" (15 NB) to 60" (1500 NB) |
| Pressure Class | 150#, 300#, 400#, 600#, 900#, 1500#, 2500# (B16.5); 75#, 150#, 300#, 400#, 600#, 900# (B16.47) |
| Grades | LF1, LF2 Class 1, LF2 Class 2, LF3, LF5, LF6, LF9, LF787 |
| Flange Types | Weld Neck, Slip-On, Blind, Socket Weld, Lap Joint, Threaded, Orifice, Long Weld Neck, Reducing |
| Flange Face | Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ), Male & Female, Tongue & Groove |
| Manufacturing Type | Forged, Ring Rolled (for large diameter) |
| Heat Treatment | Normalized, Normalized & Tempered, Quenched & Tempered |
| Impact Testing | Mandatory Charpy V-Notch Testing per ASTM A350 |
| Testing | Impact Test (Charpy V-Notch), Hydrostatic Test, PMI Test, Ultrasonic Test, Hardness Test |
| Inspection | Third Party Inspection by TUV, SGS, Bureau Veritas, Lloyd's, DNV GL, BV, ABS |
| Certifications | EN 10204 3.1B MTC, NACE MR0175, PED 2014/68/EU, CE Marked, API 6A, ASME B31.3 |
ASTM A350 LF2 Equivalent Grades
| Standard | USA | Germany | France | Japan | India | UK | China |
| CS A350 LF2 | ASTM A350 LF2 ASME SA350 LF2 | 1.0460 C22.8 | A 42 CP | SG 295 | IS 2062 | BS 1503-161 | GB 16Mn |
ASTM A350 LF2 Chemical Composition
The detailed composition of this material is given in the following table.
| Element | Composition (%) | Function |
| Carbon (C) | 0.26 max (Class 1) 0.30 max (Class 2) | Controlled for low-temperature toughness |
| Manganese (Mn) | 0.60 - 1.35 | Enhances strength and impact resistance |
| Phosphorus (P) | 0.035 max | Controlled for improved ductility |
| Sulfur (S) | 0.040 max | Minimized to prevent cold cracking |
| Silicon (Si) | 0.13 - 0.45 (Class 1) 0.15 - 0.30 (Class 2) | Acts as deoxidizer, improves toughness |
| Copper (Cu) | 0.40 max | Low-temperature toughness |
| Nickel (Ni) | 0.40 max | Improves cryogenic properties |
| Chromium (Cr) | 0.30 max | Controlled for weldability |
| Molybdenum (Mo) | 0.12 max | Low-temperature strength |
Note: Sum of Cr + Mo + Ni + V = 1.00%. Lower carbon content compared to A105 for enhanced low-temperature impact toughness.
Mechanical Properties of ASTM A350 LF2 Flanges
The mechanical properties decide the shelflife of the material. The table below gives the information about the mechanical properties of ASTM A350 LF2 Flanges.
| Property | Class 1 | Class 2 | Testing Standard |
| Tensile Strength | 485 MPa (70 ksi) minimum | 485 - 655 MPa (70-95 ksi) | ASTM A370 |
| Yield Strength (0.2% offset) | 240 MPa (35 ksi) minimum | 275 MPa (40 ksi) minimum | ASTM A370 |
| Elongation in 2" | 22% minimum | 22% minimum | ASTM A370 |
| Charpy V-Notch Impact | 15 J avg at -46-C (-50-F) | 20 J avg at -18-C (0-F) | ASTM A350 |
| Minimum Single Value | 12 J at -46-C | 15 J at -18-C | ASTM A350 |
| Hardness (Brinell) | 137-197 HB (typical) | 137-197 HB (typical) | ASTM E10 |
ASTM A350 LF2 Flange Dimensions & Pressure Rating Chart
Pressure-Temperature Ratings for Carbon Steel A350 LF2 Flanges
| Temperature -F (-C) | Class 150 | Class 300 | Class 600 | Class 900 | Class 1500 | Class 2500 |
|---|---|---|---|---|---|---|
| -50 to 100 (-46 to 38) | 290 psi | 740 psi | 1480 psi | 2220 psi | 3705 psi | 6170 psi |
| 200 (93) | 260 psi | 675 psi | 1350 psi | 2025 psi | 3375 psi | 5625 psi |
| 300 (149) | 230 psi | 655 psi | 1315 psi | 1970 psi | 3280 psi | 5470 psi |
| 400 (204) | 200 psi | 635 psi | 1270 psi | 1900 psi | 3170 psi | 5280 psi |
| 500 (260) | 170 psi | 600 psi | 1200 psi | 1795 psi | 3000 psi | 4995 psi |
| 600 (316) | 140 psi | 550 psi | 1095 psi | 1640 psi | 2735 psi | 4560 psi |
Types of ASTM A350 LF2 Flanges Available
Spectacle Blind Flange
Orifice Flange
Lap Joint Flange
Long Weld Neck Flange
Threaded Flange
Reducing Flange
Weld Neck Flange
Slip-On Flange
Socket Weld Flange
Blind Flange
Standard Flange Sizes & Weight Chart
ASTM A350 LF2 Weld Neck Flange Dimensions (ANSI B16.5) - Class 150 Sample
| NPS | Outside Diameter (mm) | Thickness (mm) | Bore (mm) | Hub Dia (mm) | Bolt Circle (mm) | No. of Bolts | Bolt Dia | Approx Weight (kg) |
|---|---|---|---|---|---|---|---|---|
| 1/2" | 90 | 11 | 21 | 35 | 60 | 4 | M12 | 0.45 |
| 1" | 108 | 13 | 33 | 50 | 79 | 4 | M12 | 0.86 |
| 2" | 152 | 16 | 60 | 75 | 121 | 4 | M16 | 1.80 |
| 4" | 229 | 19 | 114 | 127 | 190 | 8 | M16 | 5.40 |
| 6" | 267 | 21 | 168 | 184 | 229 | 8 | M19 | 8.60 |
| 8" | 330 | 24 | 219 | 238 | 286 | 8 | M19 | 14.5 |
| 12" | 483 | 29 | 324 | 346 | 432 | 12 | M22 | 36.0 |
| 16" | 597 | 32 | 419 | 448 | 546 | 16 | M25 | 64.0 |
| 24" | 813 | 44 | 610 | 651 | 756 | 20 | M32 | 150.0 |
Is ASTM A350 LF2 Good Quality for Low-Temperature Applications?
Yes, low-temperature service ASTM A350 LF2 is the industry standard low-temperature service, which is specially designed to operate in the conditions where traditional carbon steel is brittle. The low carbon content (max 0.26% in Class 1) is controlled with normal heat treatment to give a fine grained microstructure that ensures ductility and impact toughness at sub-zero temperatures. Class 1 and Class 2 are required to operate at minimum energy absorption values of 15J per flange in -46-C (-50-F) (Class 1) and 20J per flange in -18-C (0-F) to ensure that brittle fracture does not occur under thermal shock and dynamic conditions.
This is because the material has superior low-temperature behavior due to its optimized metallurgy lower carbon content lowers the ductile-to-brittle transition temperature (DBTT), and the controlled level of manganese and silicon contributes to the grain refinement during normalizing. A350 LF2 Class 1 offers an added 17-C (27-F) safety margin over A105 flanges which are restricted to -29-C (-20-F) in Arctic, cryogenic LNG and refrigeration. The specification mandates impact testing on lots, which is documented as to notch toughness, which A105 does not have.
Heat Treatment & Impact Testing Requirements
| Category | Parameter | Class 1 | Class 2 |
|---|---|---|---|
| Heat Treatment | Normalizing | Heating to 900-950-C, air cooled to room temperature | Heating to 900-950-C, air cooled to room temperature |
| Normalizing + Tempering | Not required | Tempering at 540-650-C after normalizing | |
| Quenching + Tempering | Optional (for higher strength requirements) | Optional (for higher strength requirements) | |
| Impact Testing | Test Method | Charpy V-Notch (CVN) | Charpy V-Notch (CVN) |
| Test Temperature | -46-C (-50-F) | -18-C (0-F) | |
| Minimum Average Energy (3 specimens) | 15 Joules | 20 Joules | |
| Minimum Single Value | 12 Joules | 15 Joules | |
| Specimen Size | 10 mm - 10 mm (standard) | 10 mm - 10 mm (standard) |
ASTM A350 LF2 Carbon Steel Flanges Price List 2026
| Flange Type | Size Range | Pressure Class | Indicative Price Range (USD/Piece) |
|---|---|---|---|
| Weld Neck (WN) | 1/2" - 2" | 150# | $8 - $22 |
| Weld Neck (WN) | 4" - 8" | 150# | $28 - $125 |
| Weld Neck (WN) | 10" - 24" | 150# | $180 - $680 |
| Weld Neck (WN) | 1/2" - 2" | 300# | $12 - $32 |
| Weld Neck (WN) | 4" - 8" | 300# | $48 - $195 |
| Weld Neck (WN) | 10" - 24" | 300# | $265 - $950 |
| Slip-On (SO) | 1/2" - 2" | 150# | $6 - $16 |
| Slip-On (SO) | 4" - 8" | 150# | $22 - $85 |
| Blind (BL) | 1/2" - 2" | 150# | $5 - $14 |
| Blind (BL) | 4" - 8" | 150# | $24 - $95 |
| Socket Weld (SW) | 1/2" - 2" | 150# - 600# | $9 - $38 |
Note: A350 LF2 flanges are typically 15-25% higher in price than A105 due to mandatory impact testing and specialized heat treatment requirements.
Applications of ASTM A350 LF2 Flanges in Industry
The ASTM A350 LF2 Low Temperature Carbon Steel Flanges are commonly used in many industrial applications, and some of the common industries are given below.
LNG & Cryogenic
Liquefied natural gas plant, liquid nitrogen/oxygen plant, liquid nitrogen, futile storage tanks, liquid nitrogen, tank.
Arctic/Cold Climate Operations
The oil and gas pipelines in the Arctic, off shore platforms in cold waters.
Refrigeration Systems
Refrigeration in industry, cold storage, food processing.
Chemical Processing
Low-temperature ethylene plants, cryogenic distillation, propylene systems.
Power Generation
Cold climate power generation, cryogenic energy storage, gas turbine fuel generation.
Marine Applications
LNG carriers, cold water offshore drilling, subsea pipelines.
Petrochemical
Low temperature separators, demethanizers, cold box equipment.
Why Choose ASTM A350 LF2 Flanges from Metinox Overseas?
Metinox Overseas provides certified ASTM A350 LF2 flange with compulsory impact test, full trace and available in stock upon request when there is urgent low temperature work. All flanges are produced in our ISO 9001:2015 certified plants to guarantee that all flanges satisfy high standards of notch toughness and that reports of Charpy V -notch tests are documented. EN 10204 3.1B Mill Test Certificates and impact test charts, heat treatment records and third party inspection support (TUV, SGS, DNV GL) are available at our hand. Our large stocks of Class 1 and Class 2 grades of 1/2" to 48" NB and reasonable prices provide our services to more than 60 countries with professional technical assistance in the selection of materials and adherence to codes.
ASTM A350 LF2 Flange Delivery Time & CIF Pricing by Country
| Destination Region | Major Ports / Cities | Estimated Delivery Time | Typical CIF Terms |
|---|---|---|---|
| Middle East (GCC) | Dubai, Dammam, Doha, Muscat, Kuwait, Bahrain | 7-12 Days | CIF Dubai / CIF Dammam |
| Europe | Rotterdam, Hamburg, Antwerp, Southampton, Felixstowe | 22-28 Days | CIF Rotterdam / CIF Hamburg |
| USA & Canada | Houston, New York, Los Angeles, Vancouver, Montreal | 28-35 Days | CIF Houston / CIF New York |
| Southeast Asia | Singapore, Port Klang, Manila, Jakarta | 12-18 Days | CIF Singapore / CIF Port Klang |
| Africa | Lagos, Durban, Mombasa, Alexandria | 18-25 Days | CIF Lagos / CIF Durban |
Other Types of Carbon Steel A350 LF2 Flanges
ASTM A350 LF2 Low Temperature Flanges, Carbon Steel A350 LF2 Class 1 Weld Neck Flanges, CS A350 LF2 Slip-On Flanges, ASME SA350 LF2 Blind Flanges, A350 LF2 Socket Weld Flanges, A350 LF2 Class 2 Threaded Flanges, ANSI B16.5 A350 LF2 Lap Joint Flanges, Low Temperature A350 LF2 Orifice Flanges, A350 LF2 Long Weld Neck Flanges, ASTM A350 LF2 Reducing Flanges, A350 LF2 Class 150 Flanges, A350 LF2 Class 300 Flanges, A350 LF2 RTJ Flanges.
Popular Locations Where We Supply ASTM A350 LF2 Flanges
carbon steel a350 lf2 flanges supplier in singapore, astm a350 lf2 flanges suppliers in qatar, a350 lf2 low temperature flanges suppliers in uae, astm a350 lf2 flanges suppliers in chennai, a350 lf2 class 1 flanges in mumbai, astm a350 lf2 weld neck flanges in delhi, asme sa350 lf2 flanges price list, cs a350 lf2 slip-on flanges exporter.
People Also Search For
astm a350 lf2 low temperature flanges manufacturer, a350 lf2 class 1 flanges supplier, asme sa350 lf2 flanges exporter, carbon steel a350 lf2 weld neck flanges, a350 lf2 slip-on flanges price, astm a350 lf2 blind flanges dimensions, a350 lf2 socket weld flanges specifications, a350 lf2 cryogenic flanges, astm a350 lf2 flanges price list 2026, a350 lf2 carbon steel flanges supplier.
Looking for High-Quality ASTM A350 LF2 Flanges?
Let us support your projects with quality, precision, and performance.
Frequently Asked Questions (FAQ)
A350 LF2 contain also less carbon (max 0.26% vs 0.35%) and obliging Charpy impact testing at -46-C. A105 has a minimum temperature of -29-C and LF2 Class 1 has a minimum temperature of -46-C which is more tough in cryogenic temperature application.
Class 1 is impact tested at -46-C (-50-F) and minimum average 15J, which is acceptable in cryogenic service. Tests Class 2 is tested at -18-C (0-F) with 20J minimum average, moderate cold service. Class 1 is less carbon-based (0.26 per cent maximum vs. 0.30 per cent maximum).
Yes, A350 LF2 Class 1 is very common in LNG terminals, storage tanks and piping systems in place at -162-C LNG temperature. Nonetheless, when in direct LNG contact austenitic stainless steel 304L/316L is desirable. A350 LF2 is utilized in cold service as well as vapor handling.
Compulsory normalizing (heating to 900-950-C and air cooling) of Class 1. Class 2 can be normalised at 540-650-C. Enhancing properties Quenching + tempering optional. MTCs should be accompanied by heat treatment records.
Yes, A350 LF2 can be easily welded by SMAW process (E7018, E8018-C1), GMAW (ER70S-6, ER80S-Ni1) or GTAW process. Preheat at thermal flux >25mm = 95-120-C. Stress relief is provided when the welds are post-heated. ASME Section IX qualified procedures should be used in welding.
Yes each shipment contains EN 10204 3.1B MTC with actual chemical composition, tensile properties, and Charpy V-notch impact test results at given temperature (-46-C Class 1, -18-C Class 2) giving energy values per each specimen and mean.
A 350 LF2 flange rated under ASME B16.5 is rated to service up to 427-C (800-F), which is the same as A105. They are however, mainly characterized as low temperature services. At temperatures above 427-C, replace with ASTM A182 F11/F22 alloy steel flanges.
NACE MR0175 does not comply with A350 LF2. In the case of sour service (H2S environments) compliance with hardness testing (=22 HRC max), additional traceability, and the sour service documentation are to be specified. A350 LF2 material that is compliant with NACE is available through our technical team.
Yes, we are supplying A350 LF2 flanges that are certified PED 2014/68/EU, CE marked, manufacturer declaration of conformity and co-ordinated with EU notified bodies. Besides testing and documentation, you have an extra testing and documentation according to the PED Category requirements of your pressure equipment.
Stock Items (Class 1, 1/2"-24" NB, Class 150/300/600, RF): 5-7 days ex-works. One of the manufactured to order flanges with impact testing: 4-5 weeks of time including forging, heat treatment, impact testing, and documentation. Big diameter B16.47 flanges: 5-7 weeks. Rush service on the emergency projects.
Enquire Now
Get pricing within 24 hours!
