Q: I need a material with slightly more corrosion resistance than the Super Duplex bolts I’m using. I’m using them in heated salt water for desalination and over time experiencing slight corrosion. Anything that could withstand the salt water better?
A: You have a lot of options. One may be 254 SMO bolts which offers slightly higher resistance to salt water than Super Duplex 2507 bolts. You could also go a step further and try AL6XN bolts or titanium bolts. On a scale of salt water resistance Super Duplex bolts offers good resistance, then 254 SMO slighter more, AL6XN following and titanium bolts offers the best. Both AL6XN and 254 SMO fasteners provide less strength than Super Duplex. If strength is a concern, you may want to use Titanium grade 5 bolts which provides excellent salt water resistance and greater strength compared to Duplex 2507.