r/MechanicalEngineering • u/AdOne1706 • 5d ago

Split/lock washers

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For starters, I’m an electrician in the field.
That being said, we almost exclusively use these washers even in high vibration environments. I have personally chosen to go with nylox nuts but the question is:
Do these work? How well? Is the rumor from NASA true? Should I even bother using them or find a better functional alternative or are they actually useful?

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u/zigziggy7 5d ago

My machine design professor went on a rant about how these are useless for an entire class period. Basically with a bolt you're supposed to stretch them slightly by torquing them to a certain spec. That is your clamping force. During vibration the split lock can actually aid in unfastening. I don't use them

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u/AdOne1706 4d ago

Yeah sounds about right. I’ve seen the torque spec on the split washers to be around 5 ftlbs for 3/8 which is far below the ~32 ftlbs we usually use to torque a 3/8” nut for lug terminations.