[Michael Burbidge]

When I built my 9, the kit came with mostly nyloc 3/16 lock nuts, except for the engine compartment. My 14 kit is coming with all steel lock nuts (MS21042-3). Does anyone know why?

The bigger lock nuts are easier to work with.

Besides the small size, the steel lock nuts have a larger prevailing torque value and with more variance. I'm finding 10 - 15 in/lbs and I've had a few as high as 25 in/lbs. The nylocs were typically under 5.

Michael-

 

[David Paule]

Among other reasons, they save somewhere around a pound.

Dave

 

[wirejock]

Nylocs

I thought it had something to do with heat. I used all MS21042 firewall forward.

 

[Michael Burbidge]

Yes certainly firewall forward steel locknuts are used. But I'm asking about everywhere else. I suppose it is weight.

 

[Jaypratt]

It’s a pain

Those little steel nuts suck. I use nyloc nuts..

 

[wirejock]

Lock nuts

Yes certainly firewall forward steel locknuts are used. But I'm asking about everywhere else. I suppose it is weight.

Other places, there is another lock nut that will save weight.
MS17825
It's a castleated nut with a nylon locking bushing.

 

[cvairwerks]

Might be a reduction in carrying part numbers in stock. The MS nut is approved for all locations, while the AN is not supposed to used where temps can reach above 250F.