Spring lock washers out of favor?

[zboss]

Vibration Loosening of Bolts and Threaded Fasteners

"As a result, a rationalisation of the variety of locking devices used by such major companies has occurred. For example, conventional spring lock washers are no longer specified, because it has been shown that they actually aid self loosening rather than prevent it."

Should we be switching out all our spring lock washers for a different nut type?

[exMaggieDrum]

I don't have any personal experience with spring washers failing unless they just weren't torqued down in the first place. I have seen nuts come off without spring washers. Nylocs work well but they are a pain in the rear when it is tough to get a wrench or socket on the bolt and the nut side. And you have to use the wrench or socket for the whole distance of the thread. Not a big deal for something that is not removed often but it is if it is something that has to be done a lot.

And - a new nyloc should be used every time. They are expensive and often the right one isn't available when you need it. So people reuse the old ones. Not recommended. I tend to hate nylocs and only use them for critical applications.

When used on studs you don't need a separate wrench/socket on the one side so they are easier to remove or put on but I still don't like them for anything where I have to remove them often.

One thing I do find amazing is that some places on motors no washers are used at all with no problem. My water pump">raw water pump cover is like that. The machine screws have never backed out and it vibrates like crazy.

Adhesives like locktite work well too.

But I'm going to continue to use spring washers for the most part. Even on my diesel where vibration is major.

The article you linked to is very poorly written and difficult to read but has some good stuff in there. But one of the reasons it gave for loosening (if I read it right) was when the bolt thread was not snug in the hole so it could shift in the hole. I don't think you would ever want that situation regardless of the type of locking mechanism.

This may be an issue that I just wasn't aware of.

[Canibul]

In some cases where I've had to reuse nylocks offshore I found that taking a flat bladed screwdriver of a width to span just the nylon insert and using that to deform the nylon slightly gave it some grip again. I just put the nut on a vise, with the nylon insert up and used the flat bladed screwdriver and a small hammer to slightly hammer in the visible inside edge of the nylon. It tightened the hole back up. Not as good as new no doubt, but better than nothing.

[DeepFrz]

Nord-Lock wedge-locking washers | Secure your critical bolted joints with the original lock washer from the bolting experts
I've posted this link before.

[glenn.225]

Got to say my favorite type of lock washer are Nordlocks, (two piece, stepped washers) reusable and stay put. Some times a little harder to remove but grease, oil, heat or other stuff doesn't affect them. You pay a little more for them but they work.

[roverhi]

McMaster Carr stocks Nord-Lock washers in SS. Mahalo for turning me on to them.

[Boatyarddog]

I'm using Nyloc nuts these days.
Spring locks require compression pressure to remain locked.
If the material shrinks or becomes non compressible, they loosen.
Nylocks stay put.
Use new ones, when removing and replacing.


Sent from my iPad SV Cloud Duster

[Saltyhog]

Having owned and worked on Harleys for many years, I can say with confidence, the vibration environment we have on sailboats ain't nuthin'.

On my current scoot (a 2003 model), there are very few lock washers. More common are lock-nuts. Almost universally, anyone who has worked on Harley Davidsons becomes best friends with blue (and sometimes red) loctite. On the boat, I use Nylocs for most stainless fasteners. When those are inappropriate for whatever reason, I use blue loctite. On the engine for steel fasteners, I use whatever was original to the engine + blue loctite.

[roverhi]

Nyloks can come loose on a boat. My self steering vane ripped itself off the stern of my boat because a Nylok nut backed out and fell off. After repairing the damage to the transom, reinstalling the vane and sailing to Hawaii, a couple more of the Nyloks loosened enough to allow the self steering rudder to twist a few degrees off center so it was no longer centered at the midpoint. Made hand steering a bit arduous. I'm going with Nyloks, Nord-Loks and red LocTite on every nut on the self steering in the future.

[onestepcsy37]

Never heard of nord-locks. Looked up their website but didn't find any explanation of exactly how they work. Can anyone enlighten me?

[DeepFrz]

I'm going with Nyloks, Nord-Loks and red LocTite on every nut on the self steering in the future.

Is that the belt, belt and suspenders method?

[roverhi]

Originally Posted by DeepFrz

Is that the belt, belt and suspenders method?

No, it's the belt, belt and suspender and a bit of 5200 between skin and pants method. Want to be sure it will take a bit of flesh should the bolts decide to loosen on their own.

The serrated edges of the Nord-Lock washers bite into the nut and and material being held. Sort of like the split lockwashers on steroids.

[Wotname]

Originally Posted by DeepFrz

Is that the belt, belt and suspenders method?

Nah, ya gotta use lockwire as well although some folk go staight to lockwire and leave out the the other stuff

Never seen lockwire fail but I suppose it could happen.

Anyone else seen it fail???

[JPA Cate]

Originally Posted by Wotname

Nah, ya gotta use lockwire as well although some folk go staight to lockwire and leave out the the other stuff

Never seen lockwire fail but I suppose it could happen.

Anyone else seen it fail???

Nope, sure haven't... and hope to never in the future! It (safety wire) is what finally cured the unscrewing habit the fasteners holding our gooseneck casting to the mast had for years.

There may be some cases where random unscrewing is good (pregnant GF??), but when your gooseneck wants to fall off at sea it is unsettling!

Cheers,

Jim, using Ann's computer, rolling our guts out in the lee of Babel Island.

[Orion Jim]

Originally Posted by roverhi

Nyloks can come loose on a boat. My self steering vane ripped itself off the stern of my boat because a Nylok nut backed out and fell off. After repairing the damage to the transom, reinstalling the vane and sailing to Hawaii, a couple more of the Nyloks loosened enough to allow the self steering rudder to twist a few degrees off center so it was no longer centered at the midpoint. Made hand steering a bit arduous. I'm going with Nyloks, Nord-Loks and red LocTite on every nut on the self steering in the future.

Thanks for posting this, perfect timing. My new (replacement for an old 3rd hand unit I had) Monitor will arrive in three days. My intention was to use nylock nuts and spring washers but now I'll add some locktite also. I don't want any of those mounting bolts to ever loosen.