Lock washers don't work?

[Reg]

Yet another great educational discussion on TBY! I remember that back in the day that my dad was in the aviation business, beginning with piston engines and finishing with a fleet of DC-9s, there were no split lock washers. Inside toothed, more often deformed lock nuts, and when it had to stay tight, plain old SS safety wire. There was lots of safety wire used- I think I still have several spools of it I inherited. But, I don't fly in anything I have worked on, so it doesn't get much use. Sure, they sometimes used Lok tite, but never when it just couldn't fail. Funny, but I miss the sound of radial engines and the smells of engine shops.

Hahh,
As "Young adults" we cross drilled and safety wired EVERYTHING on motorcycles (primarily Norton thumpers) of the day.
I still miss the smell of Castrol R (-:

 

[RoyJackson]

Another type of locking washer I found about recently is a Schnorr washer. These are serrated and we use them in pairs in certain applications. When torqued (when used in pairs), it takes more torque to break them loose.

 

[Renze]

Another type of locking washer I found about recently is a Schnorr washer. These are serrated and we use them in pairs in certain applications. When torqued (when used in pairs), it takes more torque to break them loose.

That sounds to me like, what we buy as Nord-lock washers... they are the best mechanical system (apart from safety wire, but wiring is too time consuming to keep up with a modern assembly line )

 

[Renze]

Yet another great educational discussion on TBY! I remember that back in the day that my dad was in the aviation business, beginning with piston engines and finishing with a fleet of DC-9s, there were no split lock washers. Inside toothed, more often deformed lock nuts, and when it had to stay tight, plain old SS safety wire.

That sounds like the engine of my 3011 which i just got running again, after rebuild.. Its 1958 design is a textbook example of effective simplicity, but somehow it was treated as a NASA rocket: connecting rods are cross drilled and locked with split pins, oil pump and suction tube are locked with wire... I couldnt get the stuff anywhere, so i just used MIG wire instead...

 

[RoyJackson]

That sounds like the engine of my 3011 which i just got running again, after rebuild.. Its 1958 design is a textbook example of effective simplicity, but somehow it was treated as a NASA rocket: connecting rods are cross drilled and locked with split pins, oil pump and suction tube are locked with wire... I couldnt get the stuff anywhere, so i just used MIG wire instead...

As long as it's stainless steel wire, you should be fine. .032"-.040" wire works really nicely.

For you guys who safety wire...if you buy the pliers, don't go nuts twisting the wire. Don't twist any tighter then you can do by hand. Weakens the wire (cold working).

 

[Renze]

... Just got me thinking... using MIG wire on a DC-9 ??

 

[czechsonofagun]

Very interesting! However I never had a lock washered nut to go lose on me - as long as it is the german way - gutntit:thumbsup:

 

[SPYDERLK]

Very interesting! However I never had a lock washered nut to go lose on me - as long as it is the german way - gutntit:thumbsup:

:thumbsup:Thats just correctly tightening the fastener. Yould get a more healthy joint using hi strength flat washers because they broaden the clamp point.
larry

 

[RoyJackson]

... Just got me thinking... using MIG wire on a DC-9 ??

No...safety wire is safety wire. In a high stress application (aerospace) in which loose fasteners can result in a catastrophy, I wouldn't suggest using anything but safety wire.
My first response was, to put it mildy, ill advised.
In Renze's application, that wire may hold up...might not. Guess using MIG wire was better then nothing though.

 

[fcamillieri]

:thumbsup:Thats just correctly tightening the fastener. Yould get a more healthy joint using hi strength flat washers because they broaden the clamp point.
larry

I would think more surface = less PSI so the fastener wouldn't be as tight.