What Is ASME SA105 Material?

ASME SA105 is one of the most commonly used carbon steel materials for forged components in pressure piping systems. It is widely applied in flanges, fittings, valves, and other pressure-containing parts where strength, reliability, and code compliance are required.Although it is often mentioned together with ASTM A105, SA105 is specifically qualified for use under the ASME Boiler and Pressure Vessel Code, making it essential for regulated engineering projects.

ASME SA105 Chemical Composition and Mechanical Properties Material Table

The ASME SA105 specification sets the following typical chemical composition limits:

ASME SA105 Chemical Composition

Element	Content (%)
Carbon (C)	≤ 0.35
Manganese (Mn)	0.60 – 1.05
Phosphorus (P)	≤ 0.035
Sulfur (S)	≤ 0.040
Silicon (Si)	0.10 – 0.35
Copper (Cu)	≤ 0.40
Nickel (Ni)	≤ 0.40
Chromium (Cr)	≤ 0.30
Molybdenum (Mo)	≤ 0.12

ASME SA105 flange material

ASME SA105 Orifice Flanges are specialized components designed for use in high-pressure and high-temperature piping systems. These flanges are forged from carbon steel in accordance with the ASME SA105 specification, which sets standards for materials used in such critical applications. The composition of SA105 materials typically includes a maximum of 0.35% carbon, 0.60-1.05% manganese, and trace amounts of phosphorus, sulfur, and silicon. This combination of elements provides the necessary strength and durability required for withstanding extreme conditions. In terms of mechanical properties, ASME SA105 Orifice Flanges exhibit a tensile strength ranging from 485 to 655 MPa, with a yield strength falling between 250 and 410 MPa. They also have an elongation of at least 22%, indicating their ability to withstand deformation under stress, and a reduction of area of 30% or more, demonstrating their ductility. Additionally, these flanges have a hardness value, measured on the Brinell scale, ranging from 137 to 217 HB. These properties collectively ensure that ASME SA105 Orifice Flanges can withstand the demanding environments they are intended for.

ASTM A105 vs. ASME SA105 — What’s the Difference?

Although the two material grades share the same chemical and mechanical requirements, there are important differences:

1. Governing Standards
ASTM A105: Defined by ASTM International
ASME SA105: Part of the ASME Boiler and Pressure Vessel Code (BPVC)

2. Code Compliance
SA105 is required for components used in ASME-code-regulated equipment, such as:
Pressure vessels
Boilers
Heat exchangers
Code-stamped piping systems

3. Material Certification
SA105 materials come with ASME-compliant Material Test Reports (MTRs) and stamped identification such as:
SA105
SA105N (normalized)
SA105 + A / N / QT (heat-treatment conditions)
This traceability is essential for code inspection and project certification.

Manufacturing and Quality Control

For SA105 components, performance depends heavily on manufacturing consistency
Typical quality control includes:
Raw material verification
Forging process control
Heat treatment monitoring
Mechanical testing
Marking and traceability
At BAOWI STEEL, SA105 forged components are produced under strict inspection procedures to ensure compliance with project and code requirements.

Conclusion

ASME SA105 is a key material for forged carbon steel components used in pressure systems. While it shares the same composition as ASTM A105, its certification under ASME standards makes it essential for regulated applications.
Understanding the difference between SA105 and A105 is not just about material properties—it directly impacts compliance, safety, and project approval.For engineering projects, choosing SA105 ensures both performance and code acceptance, making it a reliable option for critical pressure applications.