Talk:Washer (hardware)

Aren't belleville washers lock washers too? I added Fender washer, but I'm not quite sure how to define it. Ortolan88 00:10, 22 Aug 2004 (UTC)

Yes, belleville washers are somtimes used as locking devices. But only in joints with low dynamic loads. A proper pre-load (or clamp-load) is one way to keep a bolted joint from coming loose, but belleville washers usually have lower pre-loads than bolts (1/4" grade 8 capscrew will have a pre-load of about 2800 lbf, and belleville washers for 1/4" hardware might have a compressed load of 50-1000 lbf).

Bellevilles are also used as pure springs. One example is a live load joint, where flexibility is designed in. In this case bellevilles are springs, maintaing a pre-load, but not working as the locking mechanism.

Another example is a joint that experiences a lot of thermal expansion and contraction. A belleville may supply the designed pre-load, but the bolt may have an additional locking mechanism (loctite, for example) that would fail without the belleville.

A fender washer is a flat washer with an oversized O.D. This type of washer distributes the capscrew's clamp-load over a greater area.

209.102.125.87 01:47, 22 Aug 2004 (UTC)