Tag: C276 bolts for sulfuric acid

Alloy 20 vs Duplex Zeron 100 Bolts

Q: I was thinking of ordering some Duplex Zeron 100 bolts for some mild sulfuric acid. How does that compare to Alloy 20? My alloy 20 bolts are suffering some mild corrosion.

A: Zeron bolts do offer a higher level of general resistance to corrosive environments compared to grades 2205 and 2507. Yet a Duplex bolt in grade Zeron 100 will not really offer more corrosion resistance compared to Alloy 20 in a sulfuric acid environment (of course this depends on your exact corrosive environment). Since you are having issues with the Alloy 20 fasteners moving to Duplex Zeron would not be recommended. We would suggest considering a higher level of protection from sulfuric acid, and to try a Hastelloy C276 bolt which offers excellent resistance to sulfuric acid even in hot conditions.

Titanium or Hastelloy Bolts for Sulfuric Acid?

Q: I read that titanium regenerates a protective layer quickly in presence of water. Does that mean its okay to use it with sulfuric acid with steam present?

A: Titanium fasteners are probably not the best solution for sulfuric acid but may work depending on your concentration and temperature.  Titanium is best used for corrosion resistance to chlorides and salt water. For sulfuric acid, Hastelloy C276 bolts would be a much more robust solution and will be your best option for corrosion resistance to sulfuric acid for most conditions. However to be certain we would need to know the temperature and concentration of your application.