What Is ASTM A105?

1.What is ASTM A105?

ASTM A105 is a standard specification for forged carbon steel piping components used in pressure systems at ambient- and high-temperature service conditions. It primarily includes forged fittings, flanges, valves, and parts for pressure vessels. Issued by ASTM International, this specification applies to carbon steel materials that are forged and heat treated to meet demanding performance conditions.

A105 round steel is the American ASTM A105/A105M standard "Carbon Steel Forgings for Pipeline Components". A represents ordinary carbon structural steel. It is widely used in the manufacture and production of high-pressure vessels and petrochemical pipe fittings, valves, and flanges. Because this standard only stipulates one type of carbon steel forgings, A105 is also considered a forged carbon steel grade. A105 is a low-carbon steel forging, similar to Sch 20 steel pipe. There are two standards, one is the American standard "ASTMA105/A105M Carbon Steel Forgings for Pipeline Components", and the other is the Chinese standard "GB/T12228-2006 Technical Conditions for Carbon Steel Forgings for General Valves".

2.ASTM A105 Equivalent Material

Engineers and buyers often look for ASTM A105 equivalent materials when sourcing forged carbon steel components from different countries and standards. While ASTM A105 is the most widely used specification for forged flanges, fittings, and valves in North America, several comparable grades are available worldwide.
The most common direct equivalent is ASME SA105, which shares the same chemical composition, mechanical properties, and application requirements. ASTM A105N is another commonly specified grade, referring to ASTM A105 material supplied in the normalized condition for improved grain structure and mechanical consistency.
For low-temperature applications, ASTM A350 LF2 is often selected as an alternative because it provides enhanced impact toughness and better performance in cold environments.
When a cast component is required instead of a forging, ASTM A216 WCB is generally considered the closest casting equivalent to ASTM A105.
Common international equivalents include:

Region	Grade
Europe	P245GH, GS-C25
Japan	SFVC1
China	20Mn

Although these materials offer similar performance, material substitution should always be verified against project specifications, operating temperatures, pressure requirements, and applicable industry standards.
For critical applications, engineers should review material certifications and mechanical property requirements before selecting an equivalent grade.

3.ASTM A105 Temperature Range

ASTM A105 is designed for pressure piping components operating under ambient and elevated-temperature conditions. In most industrial applications, the material performs reliably within a temperature range of -20°F to 800°F (-29°C to 425°C).

4.Typical Applications of ASTM A105

Its mechanical properties make it especially well-suited for both high-temperature and high-pressure environments.

5.Chemical Composition of ASTM A105

Element	Composition (%)
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

6.Mechanical Properties of ASTM A105

Property	Value
Tensile strength (psi) min	70,000 psi
Yield strength (psi) min	36,000 psi
Elongation in 2″ (%) min	22%
Reduction of area (%) min	30%
Brinell Hardness (BHN) max	187

7.Heat Treatment Requirements

8.Certifications & Standards of ASTM A105

9.A105 vs. A105N: What’s the Difference?

So while A105 and A105N share the same chemical composition, they serve different purposes in practice depending on the operating environment, such as high-temperature or corrosive conditions that require greater structural stability.

What Products Are Made from ASTM A105?

One advantage of ASTM A105 is its versatility. Manufacturers use it to produce many forged piping components.

Product	Typical Standards
Weld Neck Flanges	ASME B16.5
Slip-On Flanges	ASME B16.5
Blind Flanges	ASME B16.5
Socket Weld Flanges	ASME B16.5
Threaded Flanges	ASME B16.5
Lap Joint Flanges	ASME B16.5
Forged Elbows	ASME B16.11
Forged Tees	ASME B16.11
Couplings	ASME B16.11
Unions	ASME B16.11
Valves	API / ASME

ASTM A105 vs. ASME SA105

ASTM A105 is a standard for forged carbon steel developed by ASTM International, while ASME SA105 is the corresponding material standard adopted by the American Society of Mechanical Engineers in its boiler and pressure vessel specifications. The two have essentially the same chemical composition, mechanical properties, and application requirements, and can be considered equivalent materials.

Feature	ASTM A105	ASME SA105
Standard Organization	ASTM International	ASME BPVC
Material Type	Forged carbon steel	Forged carbon steel
Chemical Composition	Same	Same
Mechanical Properties	Same	Same
Typical Applications	General piping systems	ASME code pressure vessels & piping
Code Compliance	ASTM standard	ASME Boiler & Pressure Vessel Code
Interchangeability	Yes (in most cases)	Yes (where ASME code applies)

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