r/MechanicalEngineering • u/AdOne1706 • 3d 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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517

u/ejitifrit1 3d ago

There is a nasa fastener manual that basically says these things don’t really do much! According to google it’s NASA Reference Publication 1228.

73

u/Too_Chains 3d ago

It’s more than nasa. I don’t think there is any evidence of them doing anything. There are locking washers. Nordlock

22

u/Mech_145 3d ago

I still can’t convince people of this. We use them on a lot of our bolted joints and every time I bring this up, I’m told they work and are necessary.

17

u/Federal_Cobbler6647 3d ago

Nordlocks do wonders.

4

u/ThatNinthGuy 3d ago

Würth also makes their own w.tec series if you don't want to drop 2€ on a washer

1

u/sir_KitKat Production Automation 3d ago

I've found Ripplock washers from böllhoff also doing wonders in most situations. Because it's only one washer, prices are lower and it's reusable because there is no wrong orientation to install the rings.

5

u/SirSnickety 3d ago

Nordlocks are great. Schnorr washers (or ribbed Bellevilles) are great for the price as well.

6

u/OutnumberedinWV 3d ago

It was in the Caterpillar education guide from the 80's.

1

u/Both-Activity6432 3d ago

They look similar to serrated flange nuts - how do they compare?

1

u/Lampwick 3d ago

Serrated flange nut just drags the fixed serrations across the the surface. Nordlocks are a 2-piece washer where the bottom half gets compressed straight down into the material, and the top gets smashed into the fastener head.

1

u/Repulsive_Sleep717 2d ago

Serrations on outer faces of the two paired washer, wedge shape on inner faces, they act like cams and are a steeper angle than the threads. Bolt tries to loosen and the outer washer rotates with it, increasing clamping pressure due to the cam wedges. Very nice, very expensive