Material Grade Specification

Carbon Steel Flanges — ASTM A105 & A350 LF2 Manufacturer

Carbon steel flange manufacturer, Mumbai. ASTM A105 (ambient/elevated temp) & A350 LF2 (low-temp, Charpy tested). All flange types, Class 150-2500.

Material Specification & Overview

Carbon steel forged flanges in ASTM A105 and A350 LF2 represent the core workhorses of industrial fluid transport piping. While A105 is specified for non-critical ambient and elevated temperature service up to 427°C, ASTM A350 LF2 is engineered with normalized heat treatment and mandatory Charpy V-notch impact testing to withstand sub-zero conditions down to -46°C without brittle failure risk.

UNS DesignationK03504 (A105) / K03011 (A350 LF2)
Governing StandardASTM A105 / ASME SA-105 & ASTM A350 LF2 / ASME SA-350

Chemical Composition (wt %)

Governing specification limits per ASTM / ASME standards. Actual values provided on EN 10204 3.1 MTC.

ElementSpecification Limit / Composition
Carbon (C)0.35 max
Manganese (Mn)0.60 - 1.05
Silicon (Si)0.10 - 0.35
Phosphorus (P)0.035 max
Sulfur (S)0.040 max
Chromium (Cr)0.30 max (residual)
Molybdenum (Mo)0.12 max (residual)
Nickel (Ni)0.40 max (residual)
Copper (Cu)0.40 max (residual)

Mechanical Properties

PropertySpecification Limit
Yield Strength (0.2% Offset)250 MPa (36 ksi) min
Tensile Strength485 MPa (70 ksi) min
Elongation (in 2 in.)22% min
Hardness187 HBW max
Charpy V-Notch ImpactNot required by spec
Service Temp Range-29°C to 427°C (-20°F to 800°F)

Pressure-Temperature Rating Reference

Service TempClass 150Class 300Class 600Class 900
Ambient (-29 to 38°C)285 psi (19.6 bar)740 psi (51.1 bar)1480 psi (102.1 bar)2220 psi (153.1 bar)
100°C (212°F)260 psi (17.9 bar)675 psi (46.6 bar)1350 psi (93.1 bar)2025 psi (139.6 bar)
200°C (392°F)230 psi (15.9 bar)655 psi (45.2 bar)1310 psi (90.3 bar)1965 psi (135.5 bar)
300°C (572°F)200 psi (13.8 bar)640 psi (44.1 bar)1280 psi (88.3 bar)1920 psi (132.4 bar)
400°C (752°F)140 psi (9.7 bar)585 psi (40.3 bar)1170 psi (80.7 bar)1755 psi (121.0 bar)

Primary Industry Applications

Oil & Gas upstream and midstream transportation lines
Refinery utility water, steam, and hydrocarbon lines
Power generation high-pressure feed water systems
Municipal water transmission and distribution mains
Chemical plant non-corrosive process streams

Related Products & Industry Guides

Frequently Asked Procurement Questions

Q: When do I need A350 LF2 instead of ASTM A105?

A: A350 LF2 is mandatory whenever minimum design metal temperature (MDMT) drops below -29°C (-20°F). A350 LF2 undergoes Charpy V-notch impact testing at -46°C (-50°F) to ensure notch toughness and prevent brittle catastrophic failure under cryogenic or cold-climate operating conditions.

Q: What is the maximum continuous service temperature for ASTM A105?

A: Per ASME B16.5 material group 1.1 tables, ASTM A105 is rated up to 427°C (800°F). Above 427°C, graphitization risk increases and structural strength drops significantly, requiring Cr-Mo alloy steel grades like F11 or F22.

Q: Is ASTM A105 identical to ASTM A105N?

A: The 'N' suffix denotes normalized heat treatment. While ASTM A105 standard permits hot forging without post-heat treatment under certain size/class conditions, Remax Forge supplies all A105 flanges in the normalized condition (A105N) as standard practice to refine grain structure and enhance mechanical uniformity.

Q: What Mill Test Reports (MTC) are supplied with Carbon Steel flanges?

A: Every shipment is accompanied by EN 10204 3.1 Certified Material Test Reports detailing actual heat heat analysis, mechanical tensile values, hardness testing, and Charpy impact values for LF2.

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