Alloy 20 (20Cb-3)

Technical Data Sheet


Chemical Composition Limits
Weight% Ni Cr Mo Mn Cu Si C S P Cb + Ta Fe
Alloy 20
32.5-35.0 19-21 2-3 2 max 3-4 1 max 0.06 max 0.035 max 0.035 max 8 X 1.0 Bal

Alloy 20 (20Cb-3) is an austenitic stainless steel which was designed for maximum resistance to acid attacks and as such has excellent resistance to hot sulfuric acid. Alloy 20 is also resistant to intergranular corrosion in the as-welded condition. At 33% nickel, Alloy 20 has practical immunity to chloride stress corrosion cracking. Alloy 20 is used is a wide variety of applications from Sulfuric acid pickling tanks, racks and heating coil, Heat Exchangers, Process piping, Chemical and petroleum process equipment etc.

Typical Mechanical Properties


Alloy Ultimate Tensile Strength MPa 0.2 % Yield Strength MPa Elongation % Hardness MAX HRC (Brinell)
Alloy 20 551.6 241.3- 30 19 (217)

Alloy 20 (20Cb-3) is available as Bar (Round), Sheet, Plate, Strip, Welding. For all stock availability contact Sales.

Bar - ASTM B473
Plate - ASME SB-463, ASME SB-464, ASTM B 463, ASTM B 464
Sheet - ASME SB-463, ASME SB-464, ASTM B 463, ASTM B 464
Strip - ASME SB-463, ASME SB-464, ASTM B 463, ASTM B 464
Wire - ASME SB-473, ASME SB-366, ASTM B 473, ASTM B 366
Weld Wire - AWS ER320LR
Other - UNS N08020, Covered Electrodes AWS E320LR

At Aircraft Materials all stock items can be shipped out within 24 hours, usually within the same day. Even cutting orders for bar or sheet can be processed and dispatched the same day, and for time-critical situations such as AOGs, we have a dedicated AOG service desk ready to help (

Thanks to our global logistics network we can source from anywhere in the world in just a few days. We use a range of transport partners to enable us to ship overnight within the U.K. and Europe and provide fast shipping solutions to the rest of the world. If your requirement is urgent we can offer a priority shipping service, but also if time is not so critical we can offer more cost-effective options to ensure you get the best value for money. To find out more about our services click here.

Every effort is made to ensure that technical specifications are accurate. However, technical specifications included herein should be used as a guideline only. All specifications are subject to change without notice.

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