Self Locking Nut (AN365) Confusion

[geotheo]

(First post so sorry if I'm not following protocol)

Building Sonex fuselage and trying to order hardware. The hardware list from the Sonex website has a section labeled "Nuts, Elastic". In this section are AN365 self-locking nuts, for instance AN365-832 (I will use the -832 in this discussion but the same applies to other nuts, e.g. -1032). Looking at the Wicks and Aircraft Spruce sites, they show that they carry the AN365-832A. After much searching, I saw the actual MILSPEC and it indicates that the "A" at the end indicates a non-metallic insert. I'm assuming that would typically mean nylon, vs. an all-metal nut. The difference I believe is that the nylon insert versions are good up to 250 degF, the non-metallic are rated higher than 250 degF.

Looking at Sonex fuselage plans, they do indeed call out the nut without the "A" suffix. But I don't see that Wicks or Spruce carry the non-"A" version. Interestingly, the "A" version is specified on other Sonex plan assemblies.

Does it matter if it is an "A" or non "A"?

geo

[gammaxy]

I think everyone just inconsistently lists the part numbers with and without the -A because almost nobody has ever seen an all metal AN365. Are they even made? AN365 is synonymous in all our minds with "nylon lock nut" no matter what the suffix at the end might indicate.

All-metal lock nuts are typically AN363--a completely different number.

The place where -A makes a difference is on bolts where -A signifies the lack of a hole for a cotterpin.

[Sonerai13]

AN-365 nuts are always "elastic stop nuts". Some of the part numbers have an "A" behind them, and some don't. The "A" does not in and of itself indicate the type of locking method. AN-365 equals an elastic stop nut in all cases. An all-metal locking nut will be a different AN or MS number, such as AN-363 or MS20500 (and others).