ASTM A105 Carbon Steel Forgings
ASTM A105 is the standard specification covering forged carbon steel piping components for ambient- and higher-temperature service in pressure systems. It can be readily manufactured to flanges, fittings, valves, and other piping components in accordance with dimensional standards such as MSS, ASME, API, EN/BS, DIN, NOSOK specifications, etc. A105 forgings are limited to a maximum weight of 4540 kg [10000 lb]. As stated in our quality manual, welding repair of defects in ASTM A105 flanges or fittings is absolutely prohibited by Metals-Piping(although it is permissible by the standard).

Massive ASTM A105 flanges available in stock(slip on, weld neck, blind, threaded).
1. Chemical Composition Requirements
| Chemical Composition of ASTM A105 | |
|---|---|
| Elements | Composition, % |
| Carbon [C] | ≤0.35 |
| Manganese [Mn] | 0.60-1.05 |
| Phosphorus [P] | ≤0.35 |
| Sulfur [S] | ≤0.40 |
| Silicon [Si] | 0.10-0.35 |
| Copper [Cu] | ≤0.40 |
| Nickel [Ni] | ≤0.40 |
| Chromium [Cr] | ≤0.30 |
| Molybdenum [Mo] | ≤0.12 |
| Vanadium [V] | ≤0.08 |
*The sum of Cr and Mo shall not exceed 0.32%.
*The carbon equivalent CE=[C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15] shall be no greater than 0.47.
2. Mechanical Properties of ASTM A105

ASTM A105 forged fittings Class 6000: elbow, tee, coupling, plug, weldolet, nipple.
| Tensile Strength min. | Yield Strength min. | Elongation min. | Reduction of Area, min. | Hardness | ||
|---|---|---|---|---|---|---|
| MPa | ksi | MPa | ksi | % | % | HBW |
| 485 | 70 | 250 | 36 | 22 | 30 | 137-187 |
3. Heat Treatment of ASTM A105
Heat treatment is not a mandatory requirement of ASTM A105 piping components. However, there are some exceptions: ASME B16.5 flanges Class 400, 900, 1500, 2500; Flanges of special design where the design pressure at the design temperature exceeds the pressure-temperature ratings of Class 300; Flanges of special design where the design pressure or temperature are not known; Forged fittings or valve parts which are over 4″ and Class 300.

API 602 forged gate valves, body: ASTM A105N, trim: 10#, Class 900.
The typical heat treatment conducted for A105 forgings includes annealing(A), normalizing(A), normalizing and tempering(NT), quenching and tempering(QT). Especially, normalizing at approximate 950°C for 2.5 hours is often required by many clients to eliminate possible internal stress in the forgings. These materials are usually marked as “ASTM A105N”.
4. Product Forms and Standards
| Product Form | Standards |
|---|---|
| Forged Flanges | ASME B16.5, ASME B16.47, MSS SP 44, EN 1092-1, NORSOK L-005, BS 4504, ASME B16.48, ASME B16.36 |
| Forged Fittings | ASME B16.11, BS 3799, MSS SP 83, MSS SP 95, MSS SP 97, GB/T14383, GB/T14626 |
| Valve & Valve Parts | ASME B16.34, API 600, API 602 |
| Boiler & Pressure Vessel | ASME Section IX |
