What Is ASTM A105?
ASTM A105 is the standard specification for carbon steel forgings for piping applications. It covers forged carbon steel flanges, fittings, valves and similar parts for pressure-containing service at ambient and moderately elevated temperatures. It is the most common forging grade behind ASME B16.5 flanges, B16.11 socket-welding and threaded fittings, and B16.20 ring-joint (RTJ) rings.
Temperature Range
A105 is rated from -29°C to 425°C in ASME B16.5 pressure-temperature tables. Long-term continuous service above about 427°C is limited by graphitization of the carbon steel (B16.5 Table 2-1.1 note) — above that range specify alloy or stainless grades instead.
Material Group (per ASME B16.5)
A105 (C-Si nominal designation) falls in Material Group 1.1 of ASME B16.5 Table 1A, sharing its pressure-temperature ratings with A350 LF2 forgings and A516 Gr. 70 plates.
Corrosion Resistance
Carbon steel like A105 performs well in neutral, alkaline and dry/non-corrosive service — Schweitzer Corrosion Resistance Tables (Part A) rate it good to excellent in media such as ammonium hydroxide, ammonium sulfide and many organic solvents. It is not recommended in acids (e.g. glacial acetic acid) and in most corrosive aqueous service it requires coating, lining, or the use of stainless grades. For exposed atmospheric piping, painting or galvanizing is standard practice.
Typical Applications
- ASME B16.5 flanges, NPS 1/2–24, Class 150–2500
- ASME B16.11 socket-welding and threaded forged fittings, NPS 1/8–4
- ASME B16.20 ring-joint (RTJ) gasket rings
- ASME B16.48 line blanks (spectacle blinds and paddles)
- Valve bodies and bonnets for oil, gas and water service
Chemistry & Mechanical Properties
Chemistry and mechanical properties (tensile strength, yield, hardness, impact values) are specified per ASTM A105 — consult the standard for exact limits. We supply mill certificates (EN 10204 3.1) with every batch.
Related Standards
- ASME B16.5 — Pipe Flanges (NPS 1/2–24)
- ASME B16.11 — Socket-Welding & Threaded Fittings
- ASME B16.20 — Metallic Gaskets & RTJ Rings
- ASME B16.48 — Line Blanks
- ASTM A350 LF2 — Low-Temperature Carbon Steel
- Our Flange Range
- Buttwelding Elbows
FAQ
What temperature range does A105 cover?
-29°C to 425°C per the ASME B16.5 Group 1.1 pressure-temperature tables. Continuous service above about 427°C is limited by graphitization.
Is A105 suitable for low temperature?
Not for subzero or low-temperature piping — for that service use ASTM A350 LF2, which is notch-toughness tested down to -46°C.
What is the difference between A105 and A105N?
A105N means normalized heat treatment. Normalized material gives more uniform properties and is often specified for thicker sections or sour service; confirm the heat treatment with your engineer.
Can A105 be used for flange Class 2500?
Yes — Group 1.1 covers Class 150 through Class 2500; the allowable pressure drops with temperature per B16.5 Table 2-1.1.
Do you provide mill certificates?
Yes — EN 10204 3.1 mill certificates and, on request, third-party inspection (SGS/BV) are available.
Need This Standard for Your Project?
We manufacture and export flanges, fittings and gaskets to ASME standards. Send your standard, size, material, and quantity — we reply within 24 hours.