Spring washer versus belleville one

[hahoresh]

There is a rumor that fastening of busbars with spring washer can be untightened along the years if used in thermal cycles environment. This is due to asymmetrical pressure on the bolt's head or the nut.
Where can I find any basis for this assumption?

In my application I use M3 bolts with spring washer to fasten cable lug to the busbar. This connection maximum current carrying is 15A. Temperature cycle regimen: daily frequency of 50C.

 

[desertfox]

Hi hahoresh

Look at this site:-

http://www.boltscience.com/pages/helicalspringwashers.htm

desertfox

 

[hahoresh]

Thanks,
please refer to a contradiction in both recommendations:

http://www.boltscience.com/pages/helicalspringwashers.htm

http://www.boltscience.com/pages/junkertestvideo.htm.

Anyway, they deal with ultra strong vibrations, whilst I use spring washers in assembly without vibration but thermal cycles. I will appreciate very much any data dealing with this.

 

[electricpete]

It has been discussed over and over in the Fastener forum and those guys say that helical spring lockwashers are useless. See here for some references:
faq404-1257


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(2B)+(2B)' ?

 

[electricpete]

thread725-131392

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(2B)+(2B)' ?