I recently assembled a large object in my basement and was pondering exactly what is the purpose of washers? The instructions called for pieces to be affixed with nuts and bolts, and sometimes with nuts, bolts and washers. Why were washers called for in some parts but not others?
In some cases, they provide a sacrificial wear surface, so that the part they’re protecting doesn’t get worn; essentially acting as bearings. They are also used simply to provide extra thickness, so that a nut can be fully tightened. Or, to prevent the nut from slipping into or gouging the hole the bolt passes through. They also provide reinforcement of thin sheet metal.
I’m assuming you are talking about flat steel washers, not lock or rubber washers.
They also spread the fastener load over a larger area.
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Anyone know why they are called washers?
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So nobody knows, then. Where’s Cecil when you need the really tough questions answered?
They provide a larger bearing surface so the fastner can be tightened more than with out one
split washers and star shaped washers are to prevent the fastener from working loose