These are for the stern gland on the prop shaft of my little sailing boat. We don't like to use dis-similar metals under the waterline due to the possibility of galvanic corrosion.
I managed to make one of these nuts round due to over tight- ening with a wrong size spanner, had to take it off with a nut splitter.
Any suggestions where I may find nuts matching the above description? I've spent quite a while Googling and all the hits I've come up with are either 5/16" nuts in mild or stainless steel, or brass (sometimes bronze) nuts in the wrong size.
Regarding the dis-similar metals, and me making one round, I was under the impression that bronze (silicon-bronze) was quite hard, I would have thought that to be this soft they were brass. Any thoughts on this?
All suggestions gratefully received. Oh, once I've got replacement nuts I shall find a spanner that's a very good fit and save it for this purpose. I don't want to go through this trouble again.
Justin.