1/8" short

[sanibel sailor]

Thin nut first. Calder has it wrong. Gerr's illustrations and text are clear and correct.

[boatpoker]

Originally Posted by skipmac

I do believe he's saying the thin nut goes on first. That's how it's stated and explained in the article he posted.

I thought his post indicated otherwise saying it was a common misconception

[evm1024]

Thin nut first.

The last nut on will unload the threads of the first nut and transfer the full clamping force onto the last nut threads. The larger nut goes last and has the most threads.

In effect the first nut becomes something like a washer.

[a64pilot]

Originally Posted by boatpoker

That is another way of doing it but what if the holes don't line up. Do you loosen the nut so the pin will go in ? That will be very hard on the key.

No, if it’s a critical torque, you can vary the engagement with a thin washer, if not you usually tighten to get alignment.
That is the way aircraft are done, and or safety wire.
Reason is that prevents loosening of the nut, they way it’s done with a prop only prevents you from losing the nut and prop. It doesn’t prevent the loosening to begin with, which is strange. I guess it’s been done that way forever and works, why change?

Then I believe if you use a prop anode nut, it is a castellated nut.
https://www.boatzincs.com/prop_nut_s...RoCbvYQAvD_BwE
If or when I go back to a fixed prop, I’m going that route as I like prop anodes, easy to change and work well.

[ggray]

Originally Posted by boatpoker

ABYC, ABS, Det Norske Veritas, SAE, Machinists Handbook, all state thinner nuts first. Hundreds of explanations on line as to why.

Here is one typical explanation

This is good to know; I assume this would apply to all double nutted applications, not just props.

Thanks!