Going Nuts

[Steveg353]

I am looking for stainless nuts that will thread onto the threaded rod that holds the the shaft packing flange. The threaded rod appears to be 1/2" but no 1/2" nuts will fit on the rod. My boatyard guy told me that the nuts are probably Tyshing thread pattern and standard or metric 1/2" nuts will not work.
Is this a common problem and are these nuts available somewhere?
Boat is a 1988 Marine Trader 38, twins, ADC135s

 

[GoneFarrell]

Do you have the old nuts to go on a thread matching hunt?

 

[bayview]

Ifall else ails you can retread the rod to SAE, not perfect but will work especially if the threads are similar in pitch.

I think the nuts should be bronze. If you can get a tap of the correct tread you could also rethread bronze nuts.

 

[psneeld]

If like mine, they are British Whitworth or British standard thread. Several threaded rods on my boat were.


The rod diameter is like SAE but the threads are different...that's why an SAE nut will thread on part way nicely, but only part way.



Got them from the same place as pictured below as shipping from Britain for some nuts was like $35.


You can google "Trawler forum british standard thread" and several threads discusss this. This is the one that the second link below is from...


https://www.trawlerforum.com/forums/s10/new-stuffing-box-nuts-48779.html







link:
https://britishfasteners.com/nuts/stainless-steel-nuts.html

 

[Steveg353]

I do have a couple of the old nuts that are still in ok shape. I have been to a couple fastener shops and they cannot match.

 

[psneeld]

I am looking for stainless nuts that will thread onto the threaded rod that holds the the shaft packing flange. The threaded rod appears to be 1/2" but no 1/2" nuts will fit on the rod. My boatyard guy told me that the nuts are probably Tyshing thread pattern and standard or metric 1/2" nuts will not work.
Is this a common problem and are these nuts available somewhere?
Boat is a 1988 Marine Trader 38, twins, ADC135s

"Tyshing thread pattern"???.... Even Google didn't recognize that one.


Sure that wasn't just another Taiwan Trawler joke?

 

[bayview]

Get a pitch gauge and calipers to measure he current threads so that you know what you are looking for.

 

[Comodave]

Have you tried McMaster Carr? They might have something that will fit.

 

[AlaskaProf]

I do have a couple of the old nuts that are still in ok shape. I have been to a couple fastener shops and they cannot match.

Tacoma Screw! You might need to send them an example, but they've never failed me.

 

[Larry M]

We had a 1981 Taiwanese build and went through the same thing on the rudder packing gland. During reassembly, after repairing the rudder, we had lost one of the nuts. I was in major boat yard and what it came down to was the threads were not standard from anywhere. We recut the threads. It wasn’t the right way but it was on the rudder. It was during the time that Taiwan was putting out the boats and were making their own hardware, unfortunately.

 

[Steveg353]

So, the nuts and threaded rod is British standard (thanks psneeld). I can order some 304ss @ $4.65 each. Would that be a waste of $$$ or should I try to find 316ss?

 

[GoneFarrell]

So long as the stud and nut are different alloys, you should be OK. 316 will usually be more "stain less."

 

[psneeld]

So, the nuts and threaded rod is British standard (thanks psneeld). I can order some 304ss @ $4.65 each. Would that be a waste of $$$ or should I try to find 316ss?

They may not be the only US supplier, but the only only I could find easily and for $20 worth of nuts at the time, wasn't worth looking further.


If worried about corrosion, slather them in corrosion blocking something.