At times spring washers can be the bane of mechanical devices. First off they should never be called lock washers as their ability to permanently hold a fastener in place is dubious at best, but there are times when they do make an adequate solution to keeping something in place or to do the job any washer is designed to do, take up space. Today I found the need for just that a pulley had to be moved out approx. 1/8" from original position which meant the stub shaft it was mounted on would not protrude allowing the fastener to be tightened to the stub shaft 1/2" fastener 3/4" OD stub shaft so I was thinking spring washer, the only problem was i didn't have any of the narrowed diameter spring washers often used under the heads of Allen head bolts which are often used in a recessed mounting. Those spring washers are usually a grade 9 just like the bolts or in metric a grade 12.9
and are smaller in OD than normal hardened spring washers.
My solution since I didn't actually need high strength holding anyway was to turn down the OD of a few standard washers to 0.020" under 3/4" By locking a few of them on a 1/2" bolt used as an arbor with sacrificial nuts
If I was worried about the holding power, I would use 2 drops of blue or 1 drop of red to secure the fastener.
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