Bolt Types

[76SeaRay]

It appears that the transom plate bolts and studs are cad plated steel with stainless steel used on the exhaust bull horns. Can anyone confirm that? I need hardware in other locations like motor mount bolts so need to decide what type to get that aren't as susceptable to corrosion. I don't want to use stainless due to the dissimilar metals issue with aluminum. I ordered all the Mercruiser OEM parts I needed (from a large national supplier who shall remain nameless) but the supplier took my money and never delivered. The are now hiding their phone number on the internet because there are so many upset customers. I need to source the parts locally.

 

[Bondo]

Can anyone confirm that?

Ayuh,..... Correct,...... 99% of the necessary bolts are grade 5s, very few are gr. 8s,....

 

[76SeaRay]

Thanks. Do you know if they are Cad plated, zinc plated or yellow zinc plated?

 

[Jeff Fro]

Wouldn't the stainless steel and cad plated steel bolts/studs have the same dis-similar metal issues?

 

[dingbat]

I don't want to use stainless due to the dissimilar metals issue with aluminum.

Nothing wrong with using mixing stainless and aluminum if you know what alloys you're dealing with.

My (mostly) aluminum outboard with held together with (mostly) stainless hardware


Generally speaking, 316 Stainless is compatible with most, if not all commercial aluminum alloys