Alloy 20

Alloy 20, commonly known as Carpenter® 20, is a nickel–chromium–molybdenum alloy developed for applications involving sulfuric acid. Its corrosion resistance also finds other uses in the chemical, food, pharmaceutical, power generation, and plastics industries. Alloy 20 resists pitting, and chloride ion corrosion and its copper content protects it from sulfuric acid.

UNS: N08020
Stock Sizes: 1/4” – 1/2” OD


  • Seamless Tube: ASTM B729
  • NACE MR0175/MR0103

Available Processing:

  • Cold Worked and Bright Annealed

Common Testing: Eddy Current, Flare, Flattening, Positive Material Identification

Chemical Composition (%)

Iron (Fe)Balance
Chromium (Cr)19-21%
Nickel (Ni)32-38%
Molybdenum (Mo)2-3%
Manganese (Mn)2% Max
Silicon (Si)1% Max
Copper (Cu)3-4%
Carbon (C)0.07% Max
Sulfur (S)0.035% Max
Phosphorus (P)0.045% Max
(Nb) + Tantalum (Ta)
8 x carbon – 1.00

Physical Properties

Density (lb/in3)0.292
Elongation (min %)30
Minimum Yield (psi)35,000
Minimum Tensile (psi)80,000
Max Hardness (HRB)95