Cotter pin size?

GrandpaKip wrote:
I have reused cotter keys on boats and trailers as long as I can remember. Unless it has been work hardened to the breaking point or so bent up it’s hard to get through, I have never seen a reason not to reuse one.

Same here. It's only job is to keep the nut from turning, it sees no stress at all.

I have reused cotter keys on boats and trailers as long as I can remember. Unless it has been work hardened to the breaking point or so bent up it’s hard to get through, I have never seen a reason not to reuse one.

opnspaces wrote:
Honestly if the bearings are adjusted correctly there is no turning force on the nut. Unless you destroy the original you can probably get away with reusing it.

I always use them till the bitter end! Exactly what you said about it doesn't take much at all to hold the nut.

The pin is there on a very good reason.....to keep the adjustable nut in position...and yes they can back off without a pin destroying the bearings/axle stub/hub over time. I've seen this happen on trailers in commercial service. RV trailers would be no different as all the axles are the same brands.

Trailer axles use different size cotter pins depending on axle brand and axle size.

Honestly if the bearings are adjusted correctly there is no turning force on the nut. Unless you destroy the original you can probably get away with reusing it.

2" x 1/8 for my 3500lb axles

Edited to correct :E

Not to hijack the thread because he got the best answer, buy the assortment package. But to continue, without using any help, who invented the cotter pin, the correct name for which is cotter key, and what were they originally used for?

The answer may surprise you.

Get an assortment they are cheap.

This probably varies by manufacturer and axle rating but try a 1/8" x 1 3/4" first. I pulled that size from Dexter.

Hardware store should know.. or google.