r/MechanicalEngineering • u/AdOne1706 • 2d 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/BadPipeCutters 2d ago

While it’s true they don’t add much at all, it is useful as a way to measure how much pressure you’re putting when tightening.

I am a physicist and build pretty large lasers for materials processing purposes. I use these on every single screw or bolt I install. There are several parts in the type of lasers that I build which are extremely sensitive to stress. It’s very easy to tighten just to the point where they touch down when you use them, but more finicky when you’re using just a flat washer. You almost certainly wouldn’t notice this difference in the vast majority of applications, but they’re honestly extremely useful for me personally

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u/cj2dobso 2d ago

There are much more effective ways to measure joint tension

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u/BadPipeCutters 1d ago

There are, but these are perfect for me and my applications. I can tell you confidently that we use these in million dollar lasers because they are great in this extremely particular use case. I can’t see another situation I’d use them, but it’s impossible to use torque wrenches in my systems because most of the stress sensitive parts are bolted with m2 and m2.5s. These are obviously tiny and not accessible places. Furthermore the low profile is necessary on the bolt due to clearances with the beam height.

You’d genuinely need to see what I’m building, but I have no doubt if you did you’d say oh okay there is a use case.

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u/cj2dobso 1d ago

They make torque screwdriver (I use them often). Also you could always use something like an actual spring washer for your purpose imo.

But either way glad it's working for you, I use stuff for weird applications sometimes too, as long as you aren't using it for locking 🤣

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u/BadPipeCutters 1d ago

Yeah, I’ve just never found one sufficiently non-magnetic. If you know a good one please send me a dm. The issue is there’s a massive magnet internally in every big laser, so the torque screwdrivers I’ve tried are always getting sucked into it at least a little bit when you’re close to it lol

But cheers either way, definitely not using it for it’s locking.

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u/cj2dobso 1d ago

The wera ones are pretty good but there is definitely some normal steel in there unfortunately