Q: We are installing bolts into a refinery wharf.  After doing a test run on a few A316 stainless steel bolts, they came back heavily corroded. Do you have an coating that can be used for salt water applications that would prevent this? Or do can you advise on another material?

A: I don’t recommend a coating but I can recommend a better material to handle the saltwater situation. Here I would suggest using either Monel or titanium bolts. Monel bolts are the go-to material for many marine applications. It is available in two forms Monel 400 which offers a strength of 83ksi ultimate tensile strength and age hardened Monel K500 for extreme strength of 160ksi UTS. Titanium bolts are also and excellent choice for saltwater corrosion. They offer excellent resistance to both rapid velocity and stagnant seawater, up to a mile deep. Titanium grade 5 fasteners are 4 times stronger than 316 at half the weight.

Q: We are installing denso jackets around several steel piles at a wharf. The jackets are going to be held together by A316 stainless steel bolts. After doing a test on a few, they came back heavily corroded. Can you suggest a material that can handle the salt water?

A: To combat seawater corrosion there are two choices depending on the situation. First, is Monel 400. Monel bolts are often the go-to for salt water corrosion resistance in marine applications – even at high velocity. The Navy often uses Monel 400 for sea vessel and Monel K500 bolts when a combination of salt water resistance and high strength is needed. The only time they can show pitting and crevice corrosion is in stagnant water. The other option you have are titanium bolts. Titanium is renowned to salt water resistance and can handle both rapidly moving and stagnant waters. Titanium screws can reside in sea water for decades – up to a mile deep – without showing signs of corrosion. Both Monel and Titanium are good candidates for preventing salt water corrosion.