Warbird Information Exchange

H, I'm after the modern MS - number that replaced the old AN7502-1 wheel nuts and their associated AN AN7503-1 washers. I haven't been able to tie-up the suffix for the -1 number to the current range of MS21045 nut or the MS21258 washer series. Does anyone have the exact new suffix for the old -1 parts? Many thanks.

AN7502 was superseded by MS21025. Dash umbers should be the same.

Yes, I had understood that the suffix would remain constant, however, no-one seems to list a -1, (the lowest dash number I can find a reference to appears to be a -15 in the MS21025 range) and the closest physical dimension match seems to be a 23. Unusually I can't find a direct interchange chart.

C model Mustang uses a AN7502-1 nut on the main gear, The P-40M and N as well as a Stearman use a 32A510-1 on the main gear. Couldn't find the thread info on the Mustang axle, but the P-40 and the Stearman are threaded 1 7/16ths. I'd suspect that the MS21025-23 is the nut you are looking for.

I looked around for a conversion and found nothing for a -1 size either.

I did find an old FAA letter where an AN7502 axle nut had failed on a Convair airliner, and was found to have a tensile strength of 87,000 PSI. It was recommended to use the newer MS21025 specification nut that has a tensile strength of of 140,000 PSI.

When reading the prior posts above, I assumed a switch from AN to the MS numbering system was just that, a change of numbers. I was unaware the part was actually being superseded in strength.

I will be thinking about this the next time I replace an axle nut, or I see a video of a wheel coming off an axle!

https://worldwarwings.com/f7f-tigercat- ... is-monday/

Phil

_________________
A man's got to know his limitations.

It's the T-6 we need the details for.

IPC for the Canadian Harvard, dated 1 Jan 53, shows the main wheel nut to be a B10018-2, with a listed alternative being an AN7502-23.

Perfect, thank you

No sweat. doing parts chases can be a blast at times and a hair puller at others...