Nickel Alloys

Alloy 20

Chemical Composition %
C Cb Cr Cu Mn Mo Ni P S Si Ta
Max 8 times     Max     Max Max Max 8 times
0.07 Carbon-1.00 19.0-21.0 3.0-4.0 2.0 2.0-3.0 32.0-38.0 0.045 0.035 1.0 Carbon-1.00


Seamless Hot Finished Tubes and Hollow Bars , Solution Annealed.
Sizes from 40 mm OD to 130 mm OD in various wall thicknesses.

Also available in Round Bar up to 165 mm dia.


B 729

UNS - N08020


Alloy 20 is one of the so-called "Super" stainless steels that was designed for maximum resistance to acid attack. It's nickel, chromium, molybdenum and copper content contribute to its overall resistance to chlorideon stress corrosion cracking and general pitting attack. The alloy is stabilized with columbium to minimize carbide precipitation during welding. It has good mechanical properties and can be fabricated with comparative ease. Athough the alloy was designed for use in sulfuric acid related industries, it finds wide usage throughout the chemical processing industry. It also is used for processing pharmaceuticals, food, gasoline, solvents, plastics, explosives, synthetic fibers and many other products.

Design Features

  • Superior resistance to stress-corrosion cracking in boiling 20 to 40% sulfuric acid.
  • Excellent general corrosion resistance to sulfuric acid.
  • Excellent resistance to chloride stress corrosion cracking.
  • Excellent mechanical properties and fabricability.
  • Minimal carbide precipitation during welding.

Typical Applications

Chemical and allied industries
Food and dye production
Heat exchangers
SO 2 scrubbers and other severe environments
Pickling racks

Tensile Requirements

Tensile Strength (KSI) 80
Yield Strength (KSI) 35KSI can be converted to MPA (Megapascals) by multiplying by 6.895.


All data provided is for information and guidance only. Information above is not for design purposes and comes without warranty or guarantee with respect to the subject matter or fitness for purpose.