Extra Pexel Free Refinery

Iso-Corrosion Curves: 

Sulfuric acid one of the most common acids used in industry presents a host of corrosion problems. To counteract this, there are a few specialty metal fasteners that can provide protection. Alloy 20 fasteners provide good performance in hot sulfuric acid. More specifically they offer good resistance to stress-corrosion cracking in boiling sulfuric acid at specific range of 20% to 40% concentration, as well as general sulfuric acid resistance. For higher concentrations, Inconel 625 experiences less than 5 mils (0.005”) per year in any concentration to 80% acid up to 100°F.  Hastelloy C276 and C22 screws provide slightly better protection, than Inconel. Zirconium screws take protection to the next level, usable at temperatures well above boiling and at acid concentrations up to 70%. As with HCl, tantalum offers the best resistance to sulfuric acid but this comes with a high price tag. 

Sulfuric Acid Comparison Chart




Aqueous Corrosion Data


















































Alloy 20 Sulfuric Acid Performance

Alloy 20 Iso Sulfuric Acid 4 June 2021













Hastelloy B2 Sulfuric Acid Performance

B2 Sulfuric Acid

















Hastelloy B3 Sulfuric Acid Performance

B3 Sulfuric

Hastelloy C22 Sulfuric Acid Performance

C22 Sulfuric Acid
















Hastelloy C276 Sulfuric Acid Performance

C276 H2SO4 IsoCorrosion

















Incoloy 825 Sulfuric Acid Performance

Incoloy 825 Sulfuric Acid

Inconel 625 Sulfuric Acid Performance

Inconel 625 Sulfuric Acid

Tantalum Sulfuric Acid Performance

Specialty Metal H2SO4 Iso Corrosion Curve

Not sure what material is best for your application?

Contact an Expert

Use Our Material Selector


Our material experts are ready to help guide you through your specific application.

Contact an Expert