Q: I have a deep sea marine application that requires saltwater resistance and tensile strength around 125ksi. In addition to the saltwater and strength parameters, I’m also dealing with waters that can be stagnant. Not sure if that makes a difference. Would Monel K500 be a good choice.

A: Monel K500 bolts would definitely meet the strength requirements you have and provides excellent in salt water environments. My only concern would be the stagnant seawater, which can sometimes cause pitting. A better choice may be Grade 5 titanium bolts. Titanium grade 5 offers up to 148ksi of tensile strength and performs well in deep stagnant saltwater. Definitely worth considering.

A: Monel 400‘s only Achilles heel in terms of salt water situations usually occurs in stagnant waters where is can experience crevice and pitting corrosion. For still seawater, I would suggest Titanium grade 2 fasteners, which is known for its high resistance to sea water and all chloride environments, even at high depths and temperatures. If you need higher strength, you can always go with grade 5 bolts which are twice as strong as grade 2.