Lock washers

[steffan]

I wasn't sure what the best place to put this, but thought it was interesting and certainly applicable to most of us:

http://hillcountryengineering.com/w...it-Lockwashers-Separating-Myth-from-Truth.pdf

 

[Tapage]

pretty good info .. and true broken myth to me ..

 

[crushers]

i will disagree, cause i usually do.
have you never seen how the underside of the bolt is scored when removing? those two teeth and the spring tension does lock the bolt.
maybe not as good as the star lock
and definately not as good as these:
http://www.nord-lock.com/wp-content/uploads/2012/05/NL-washers_product-brochure_70025EN_201203.pdf
but they do lock the bolt from turning ...

 

[steffan]

You know, it's hard to argue with the science but I too have had more than one (the good ones anyway) split washer bite in and hold the nut from turning so I'm not quite sure of their wordage... Maybe it's a definition thing

 

[crushers]

i am thinking more of a liablity issue ...
"don't do this" covers their ass if the shuttle came crashing down,

plus it allows them to increase the budget to cover the more expensive star locks ... (pulling that one out my butt)

 

[Rwhat]

I also have to disagree. Almost every fastner I have used has had lock washers used. Not star washers. alot of aerospace fastners don't use lock washers. It's mostly flat washers with thread lock and staking with epoxy of the hardware.

I work sometimes in vibe and acoustic testing that simulates launching of spacecraft and rarely see hardware loosen. Unless it wasn't torqued to spec or wrong hardware used.

 

[scottm]

The shop I'm at builds custom automated production machinery. Lots of vibrations. We have occasional debates about using lock washers, I'm on the side of properly torquing without lock washers. I have seen lock washers break and cause a fastener to loosen during use. I believe automotive has eliminated the spring washer, except when they are unable to torque fasteners adequately, as in sheet metal. I build a lot of machines that put screws in auto assemblies, they almost never use lock washers. They do carefully measure torque and rotations on every screw in every part.

 

[FJ60Seth]

I don't think my 85 Mercedes has a single lock washer. Spec is to loctite every nut that's not nylock.

 

[SM Racing]

I can't stand split lock washers. I try to avoid using them any way possible. For some reason they never seem to do anything more than cause problems for things I have worked on.