Zinc plate bolt

[HappyKamper]

I'm replacing my stern zinc plate. One of the bolts snapped off. I realize one bolt is stainless steel. The other bolt is either bronze or brass? Does anyone know what metal it would be? I think its a differnet metal for its grounding properties?

 

[TJM]

I am confused by the question. "Stern zinc plate"?

Generically, you always want to use similar fasteners in an assembly because of galvanic corrosion. This includes the washers and nuts. Bronze is the alloy of choice over brass. Bronze is an alloy of Copper and Tin.
Brass is copper and zinc. The zinc dissolves quickly and leaves the copper sponge like and brittle.

 

[WALSHIE]

On my Silverton, two 3/8" SS rods protrude from the hull to hold the "license plate". I'm surprised one of your bolts are brass / bronze. Can you access it from the inside bilge? Maybe remove completely and find a new one?

 

[HappyKamper]

On my Silverton, two 3/8" SS rods protrude from the hull to hold the "license plate". I'm surprised one of your bolts are brass / bronze. Can you access it from the inside bilge? Maybe remove completely and find a new one?

I can remove it completly. Its a threaded rod. Nuts/ washers on both sides of the transom. Then the zinc followed by a washer and another nut.
From what I understand, one threaded rod is stainless steel and the other either brass or bronze? The brass or bronze rod has a grounding wire connected to it. The stainless does conduct electricity for proper grounding.