wrote in message
oups.com...
I am working with 40 year old plans that call out AN365-6 Nuts.
Since they are used in conjunction with AN6 Bolts (24 of them) to
attach the main spars together, I am assuming they are locknuts.
Is the AN363-624 Metal Lock Nut a good match or good substitution?

Yes ... AN363 are a suitable and cheaper alternative. The main difference is
that they can be used in higher temperature applications because they don't
have the nyloc insert (which I don't think it that important in a glider).
Same strength though. Most engineers use metal-loc bolts in preference to
Nyloc's these days. You could also use a MS21042 and a whole lot of other
part numbers. See the interchangability chart on the MS21042 data sheet (get
from STINET on the web). Of course you could also use the MS20365 as the
direct replacement for the old AN365. Provided that the bolt is loaded in
shear (and it sounds like they are the wing attach fitting bolts so I assume
they will be) you have little to worry about with respect to the
substitution.

I have question for you on the Prue sailplane which is way off topic and I
will take that up with you direct - hope you don't mind.



Gotta have something to hold 49 feet of wings together.
Prue Super
Circa 1963 Standard Class Sailplane.
15 meter all metal 35:1 L/D

Clark