Products Overview
ASTM A423 (ASME SA423) is a standard specification for low-alloy steel tubes, available in both seamless and electric resistance welded (ERW) forms.
These tubes are widely used in pressure-containing applications such as economizers, heat exchangers, and piping systems, where corrosion resistance, high strength, and reliability are critical.
ASTM A423 and ASME SA423 are identical standards issued by different organizations, and all requirements apply equally to both.
Grades and Classification
ASTM A423 covers three grades:
Grade 1
Grade 2
Grade 3
The grade selection depends on the mechanical requirements, chemical composition, and intended service conditions.
Chemical Composition (%)
| Element | Grade 1 | Grade 2 | Grade 3 |
|---|---|---|---|
| Carbon (C) | ≤ 0.15 | ≤ 0.15 | ≤ 0.15 |
| Manganese (Mn) | ≤ 0.55 | 0.50–1.00 | 0.70–1.40 |
| Phosphorus (P) | 0.06–0.16 | ≤ 0.04 | ≤ 0.02 |
| Sulfur (S) | ≤ 0.06 | ≤ 0.05 | ≤ 0.02 |
| Silicon (Si) | ≥ 0.10 | - | ≤ 0.55 |
| Copper (Cu) | 0.20–0.60 | 0.30–1.00 | 0.25–0.45 |
| Chromium (Cr) | 0.24–1.31 | - | - |
| Nickel (Ni) | 0.20–0.70 | 0.40–1.10 | ≤ 0.50 |
| Molybdenum (Mo) | - | ≥ 0.10 | ≤ 0.20 |
| Antimony (Sb) | - | - | 0.05–0.15 |
This composition ensures excellent corrosion resistance, weldability, and mechanical performance under demanding conditions.
Mechanical Properties
| Property | Grade 1 & 2 | Grade 3 |
|---|---|---|
| Tensile Strength (MPa) | ≥ 415 | ≥ 380 |
| Yield Strength (MPa) | ≥ 255 | ≥ 230 |
| Elongation (%) | ≥ 25 | ≥ 35 |
| Hardness | ≤ 170 HBW / 87 HRBW | ≤ 170 HBW / 87 HRBW |
Testing methods include tensile tests, hardness tests, flattening tests (seamless pipe), flaring tests (welded pipe), flange tests, and reverse flattening tests, in accordance with ASTM A450.
Note: Mechanical properties do not apply to tubes smaller than 1/4 in (3.2 mm) in inside diameter or 0.015 in (0.4 mm) in thickness.
Manufacturing Process
ASTM A423 tubes can be manufactured using:
Seamless Process – Steel pipe without welds, offering uniform stress distribution, hot or cold finished, ideal for high-strength applications.
ERW (Electric Resistance Welded) Process – Fast production, cost-effective, suitable for medium-pressure applications.
Heat treatment is required to meet the standard, usually through normalizing, which involves:
Heating slightly above the critical temperature
Holding for a specified period
Air cooling slowly
Normalizing improves grain structure, machinability, mechanical properties, and eliminates internal stresses.
Products Dimensions
Outside Diameter: 1/2 in – 5 in [12.7 mm – 127 mm]
Wall Thickness: 0.035 in – 0.500 in [0.9 mm – 12.7 mm]
Custom sizes are available on request, provided they meet ASTM A423 requirements.
Products Applications
ASTM A423 steel tubes are ideal for:
Economizers and heat exchangers
Boilers and pressure vessels
Industrial piping under corrosive or high-temperature environments
Structural tubing in engineering projects where corrosion resistance is required
ASTM A423 / ASME SA423 steel tubes combine high strength, corrosion resistance, and reliable performance. The availability of seamless and ERW processes, multiple grades, and heat treatment options makes it a versatile choice for industrial, chemical, and energy applications.
By selecting ASTM A423 tubes, engineers and manufacturers gain durable, cost-effective, and high-performance solutions for a wide range of pressure-containing components.
What is the chemical composition of ASTM A423 Grade 1?
The chemical compositions present in the A423 Gr 1 grade are carbon, phosphorus, manganese, sulfur, copper, and silicon. The high content of carbon, manganese, and sulfur provides improved oxidation resistance, pitting resistance to an acidic environment, crevice resistance, and stress corrosion cracking resistance.
What is SA 423 material?
ASTM A423 Weathering Steel Pipes Gr. 1 is popularly used in outdoor sculptures. ASTM A423 Corten Steel Tubes GRADE 1 is also used in bridge and other large structural applications. The chemical elements present in this Corten steel tube are carbon, phosphorus, manganese, sulfur, copper, silicon.
What are the common sizes and dimensions of ASTM A423 pipes?
ASTM A423 pipes are available in a variety of outer diameters, wall thicknesses, and lengths, depending on whether they are seamless or welded. The standard covers nominal pipe sizes ranging from 1/8 inch to 24 inches, with wall thickness and length varying according to application requirements.
What are the mechanical properties of ASTM A423 pipes?
These pipes are designed for high-temperature applications and therefore have high tensile strength, yield strength, and creep resistance. Typical properties include a tensile strength of 415–550 MPa, yield strength of 205–275 MPa, and elongation suitable for forming and welding. Exact values depend on the pipe grade and wall thickness.
Where are ASTM A423 pipes commonly used?
ASTM A423 pipes are widely used in boilers, heat exchangers, superheaters, and power plant equipment. They are ideal for piping systems carrying high-temperature steam, hot liquids, or gases, where corrosion resistance and dimensional stability under heat are required.
