Belleville Washer Experiences?

[WCL]

What types of applications have you successfully and not successfully used Belleville washers?
I have an application where multiple M20 grade 10.9 capscrews are used to hold a cover on a housing. The external loading into the cover sometimes is high enough to cause the cover to slip eventually causing the capscrews to loosen. Would a Belleville washer(s) provide any benefit?

Thanks for your comments!

 

[unclesyd]

Here are the website of two people that make Disc Spring that I have worked with. It is best to send them a drawing and the with all the physical parameters of the bolted connection you have

http://www.fandisc.com/Index.html

http://www.keybellevilles.com/

Without more information it sounds as you either don’t have enough preload or you need a higher strength fastener. A disc spring will not substitute for the proper strength fastener tightened to the proper preload.
If you can come back with more details of the connection like loads, no of bolts, torque values, etc.

 

[CoryPad]

I agree with [blue]unclesyd[/blue]. A conical washer will not fix the problem of insufficient preload.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[RiBeneke]

I think that a high tensile capscrew like Gr 10.9 should never be used with any kind of spring washer or lock washer as the loads are too high. Use correct preload (part-turn method rather than torque) and perhaps hardened steel flat washers under the heads.

 

[MintJulep]

Belleville "washers" are springs.

Think about your joint design with a coil spring where you are planing to use a Belleville washer. Does it seem ridiculous? If so then it is clearly not a good application for a Belleville either.