Lock Washers: What is Used Where, and Why?

I'm putting discs on an old Ford 8" so I'm mixing and matching hardware. There are spots that definitely need lock washers, but how do you determine what to use where? Split washers, internal tooth, external tooth, maybe a flat washer and a nylock nut or "Locktite".

How do you decide what to use in a given application?

 

I think this would make a wonderful tech thread. I know it is not tech week. I would however like to see it answered from a technical standpoint, not a "this is how I have always done it, and never had problems."

I look forward to what answers will come out of this thread! It is threads like this that make us all better builders, and make the hobby safer for everyone on the street.

 

I guess I did not realize that December was tech month. What can you guys come up with?

 

Easy way?

Look around on the car, the mechanical bonds/unions/connections, get a split one.

Internal tooth: Electrical bonding in 90% of the applications.

Follow suit.

 

My background is as an aircraft mechanic primarily. Here is my offering :

Toothed lock washers are mainly to assure electrical conductivity.

Split lock washers tend to damage the finish on the nut and the underlying structure. This invites corrosion.

Nylon lock nuts are great, but can't be subjected to high heat.

Metal lock nuts are tops for high heat applications.

I almost always use flat washers and a locknut of some sort on most of my car applications. This keeps corrosion at bay due to no finish damage and still assure security of the torque.

 

Went to a locktite seminar for 4 hours at work,according to the factory rep. lockwashers are from the stone ages,not good for anything ! maybe trying to sell more product.

 

Lockwashers, especially the split ones are as close to useless as an icemaker in antarctica. By the time the bolt will have loosened enough to bring it's "spring" action into affect, you have lost way more clamping load than is necessary to have a safely bolted joint. I use them nowhere on a car. Like was mentioned, the toothed washers are good at maintaining a contact under a bolted electrical connection.

Locknuts are the real solution along with locktite on blind bolted assemblies. Hard to argue against safety wire, but it's a bit much work for most spots.

 

I usually only use split lock washers if I'm replacing a bolt and it originally had one. The way I figure it, the factory did lots of testing to figure out torque specs, bolt selection etc. so they obviously know what to put where.

I generally use blue loctite on most bolts that I'm installing and I don't know what was there originally.

Other's have already mentioned about tooth ones, so I won't go there.

On a similar note, it's surprising how many people don't know how to properly install flat washers. You put the side with the rounded edges against the head of the bolt. Because the edges are rounded and there's a filet where the head meets the shank on the bolt, it's less likely to shear off the head.

 

Flat washers under both the bolt head and the nut?

 

Usually, when I'm bolting something together that will need both a bolt and a nut, I'll use a flat washer under the bolt, and a serrated flange nut.

 

lock washers are not advisable. you only have to have the proper torque on a bolt , that stretches the bolt, and keeps it tight.

 

Everyone has been reading Carroll Smiths books by the look of these answers. I read one of them recently and it totally changed (read educated) my approach to such things.

Some of my stuff still has spring washers but most stuff now does not. The only places I used them is where I assembled stuff prior to reading the book or where they are OEM parts.

Pete

 

Safety wire

 

If you are rebuilding for show and factory specs , you don't have a choice . I don't like them and never did ! I like the flat washer with a self locking plactic or metal nut where I can use them . I use Loctite on most bolts except interior parts . I hate to see a nice paint job on a car where somebody used a split lock washer and knicked the paint ! All that work and a 2 cent parts digs your paint up .

 

I try to avoid using any. I always thought they were a trouble spot and use a tension washer instead and lock nuts .

 

I got nylocks for the drag link with my axle kit but was going to put castellated nuts and cotter pins on such a critical connection. Or am I underrating nylocks?

 

Good start on what can be a great thread. Maybe this'll help.

The two most common flat washer proper purposes are:

• 1. To distribute the pressure of the nut or bolt evenly over the part being secured, reducing the chance of damage thereto, and
• 2. To provide a smooth surface for the nut or bolt to bear on, making it less likely to loosen as a result of an uneven fastening surface.

I'm really waiting for the experts to weigh in who have hot rod and/or industry experience.

 

Lock washers have been around for a longtime & thats because they work!! All those other things are just "better mouse traps"! The idea is to hold pressure against the head of the nut or the bolt & that keeps it from loosening, not rocket science,same as someone mentioned about bolt stretch. If ya use almost anything else it fights ya all the way off when your taking something apart.
As far as safety wire goes its a old method ,was good in 1925!! its slow to install, rusts(then ya got nothing).(maybe if it wasn't mentioned this post wouldn't have been considered "traditional"!!lol).
Someone mentioned that it "marks the surface & rusts".those dig mark also helps for the bolt or nut to dig in & stay put.
Only time i can see using a crimpnut is when something is behind something else & hard to reach.Most everything is a pain in the ass when removing a nut or bolt.How many time ya have a nyloc or crimp nut on a application, its sticking way out & has 2 threads left & its wobbling all over the place!!
jimV

 

I work in manufacturing where our machine is French made. They do not use split lock washers any where. They use a regular thickness washer instead. However this washer is bellvilled and has serreted lines running from outside edge to center. These bolts always give a "CRACK" when started to be loosened. They seem like an intelligent idea.....as you do not need both a washer and lock washer. Not sure where to get these state side as we get ours through the machine manufacture.I have seen a cheep version that is much thinner but would also require a washer.Let me know if anyone needs pics.

 

Not so, on the lock washer. As soon as you torque it down, the spring action
is MOST definitely in effect!
They did not use them all those years just to add weight or dig into the finish.

 

Good post.

I like AN washers in some areas.
They're the small OD flat washer that is just a touch larger than the measurement across the nut or bolt extreme OD at the hex points and not the flats.
Easily found in thin and thicker versions and usually cad-iridited a gold color.

I like Nylock nuts - and there are Nylock bolts as well, but the positive locking of a cotter pin on a castellated nut is the way to go on pitman arms and the like.

If you have a deep reach and the nut well isn't overly large you can use allen nuts.
Not a typo, there is such a thing.

 

These washers sound an a bit lot like the ones we use at the bicycle shop (where many of the original ideas were cooked up by the French and Italians) behind the axle nuts on solid axle hubs, but we only have a couple of sizes. Likewise we have flanged nuts, but only a couple of sizes.

I'm hearing of a lot of stuff for the first time in this thread:
Allen nuts
Tension washers
Crimpnuts

I think I need to go to remedial shop class...

 

All work equally well, actually I use what's in my scrounge tray. Look for the correct diameter and use what I got. When I'm all out of 3/8 for example, I buy a new stock of split.

 

The biggest problem with this is both tightening and loosening the tie rod end with a NyLock can be about impossible. The NyLock will cause the tapered joint to spin instead of seating and you'll spend all day trying to tighten or lossen the end.

 

I've been using split lock washers with no problems for 50+ years, and will continue to use them. I do make sure to use grade #8 on everything - the cheaper ones aren't worth buying. I also never, never re-use a lock washer, always use a new one.

 

Good point.

That's whats happened on a very nice A coupe I looked over for a friend a few days back.
Looked like the tie rod end stud was bent, but more than likely it couldn't pull it far enough down to lock the taper.
Which . . . made the stud look bent.

The guys are reporting the tie rod stud isn't drilled, but it probably is and the hole is full of grease or crud.

 

I,ve got heims instead of rod ends, but will drill the bolt.

 

Great Sunday morning reading. Thanks guys.

 

Use stainless safety wire and you won't have that problem

And it has to be correctly installed, but there ain't nuthin purtier than some nice, tightly twisted safety wire

 

On the tie rod end, the taper should be clean when you assemble it. Then the taper will bite and allow you to get a nylock on there. I use them on my 54, for ease of install/removal. And nobody but me sees them. They work well.

Here in NJ the racing police require cotter pins/safety wire on all steering componants. Yeah, the State Police have a racing division that goes to the tracks.

On my roadster, I use castle nuts and cotter pins, cause that's the way it ahould be.