There are several ways to lock a nut into place during an assembly.

 

Lock washers or split washers.

Double nutting, first nut tight against the work and the 2nd tight against the first nut.

Acorn nuts, those domed top nuts with the plastic inserts 

Metal bend up ears on a metal washer

A hole through the bolt through which a carter pin or wire is threaded and attached.

Tack Welding

 

 

This type locknut is popular with millwrights and indeed is hardly suitable for any other king of work. A plain nut is slotted with a saw, as shown, and the small part is driven down into a previously made center-punch mark. J. B, Murphy

 

Any other ways to lock a nut into place?

Accidental cross threading has always worked well for me :blink:

1. If you never plan on removing the nut, you can peen the top of the bolt, mushrooming it slightly.

 

2. One can take a center punch and punch on the interface between the nut and bolt, deforming some of the threads.  Still possible to remove, but difficult.

 

3. There are machine nuts that are slightly oval shaped on one end.  Requires a lot of torque to put on, and a lot of umph to get off.  I do not remember their name.

My favorite method is to leave the nut on so long that it rusts so much it becomes a weld.  Still possible to brake apart, sometimes.  

Whack the bolt or nut with a hammer a few times? Or you could give it to my brother.

 

For cars or stuff that it really mattered on, my dad was crazy about Loctite #2. He always said don't use #1 unless you really, really don't want to get it back off again.

Nord-lock washers, Safety wire, several iterations of deformed thread nuts, superbolts/nuts, tensioned studs, , etc etc...
I like Glenn's staked nut, you can always grind out the deformed metal and re-stake in a different spot. Might not even need the saw cut.

Proper tork also helps. A bolt stretches ever so slightly. A grade 0, 3, 5 and 8 bolt all have different specks, and a fine thread clamps tighter than a corse. Longer bolts are also more resistant to loosening do to vibration.
Lube the threads and use of washers will require less tork to get the same stretch.

I use Loctite as well, Red as a rule, can always use a propane torch to warm it up to get off.  This is what we use on Wood Chippers knifes, brush hog blades, most all bolts on farm machinery that spins fast, really don't like those things flying off. 

 

We also use the lock nuts with one or two sides dimpled in.  Not for dangerous areas though.       

There are several ways to lock a nut into place during an assembly.

 

Lock washers or split washers.

Double nutting, first nut tight against the work and the 2nd tight against the first nut.

Acorn nuts, those domed top nuts with the plastic inserts 

Metal bend up ears on a metal washer

A hole through the bolt through which a carter pin or wire is threaded and attached.

Tack Welding

 

Locknut.jpg

 

This type locknut is popular with millwrights and indeed is hardly suitable for any other king of work. A plain nut is slotted with a saw, as shown, and the small part is driven down into a previously made center-punch mark. J. B, Murphy

 

Any other ways to lock a nut into place?

Your list is fairly complete but if you will forgive me for making these corrections:

 

1.  An Acorn nut is actually not a locking nut.  The type nut you are referring to is often called a Nylock nut, named for the nylon insert that keeps it from coming loose.

 

2.  It is actually called a "Cotter Pin", not a Carter Pin.

beammeupscotty,

That is what makes the site so great, things get corrected in the next post or two.

We encourage corrections even if it is me getting corrected. LOL

We had a co-worker some years back, a very big fellow, who managed to tighten1/2-13 nuts onto 1/2-20 bolts. They're still in place, despite our best efforts.

My preference is for spring-type lock washers.

So, Glenn. When are you going to instal the "edit Charles's typo, spelling and and adaptive text screw up button? ;-)

and then there are split pins and roll pins(spring dowels) and split washers are spring washers

TC bolts are a bear to take off. Not nessesarily locking, but they hold beams together without fail so I think they may sort of count. Once the bolts are "snapped" You need a three foot cheater bar on your spud wrench and a lot of muscle to break them loose.

-Crazy Ivan

Not to mention Belville washers.  How many of you guys have ever encountered them?

I have an old friend who always refers to an oxy-acetylene cutting torch as a "heat wrench."  A solution to the erroneous idea of "that nut will never have to be removed."

 

Loosely,

George M. 

  

 

The Belleville is a disk spring that applies pressure to the connection once you clamp down on it with the proper amount of force. The advantage of this washer is that it applies clamping pressure along a continuous arc pattern, instead of concentrating it at one point the way a split-ring lockwasher does. While you should use a split-ring washer only at the nut end of the connection (normally), you can use Belleville washers in tandem. One at the nut end and one at the bolt head end. This is a common way to use these washers, especially when assembling bus bar.

Most often, you'll find Belleville washers in applications where you have to connect bare, soft aluminum to aluminum or copper, or where you have conditions of high current loading or cycling. These washers do wonders for accommodating thermal cycling,

 

Disk Spring Handbook

 

Disk Spring Calculator

"Your list is fairly complete but..."

 

Thanks, Beam.  Thought I was going crazy for a minute!

 

Personally, I always stake a nut that I don't want coming loose, though I've never done it like in the OP.  This should only be used when you really don't want the nut to work loose, though, as it can be a pain to undo.

If your working with stainless hardware just make sure the bolt and nut are very clean and the friction when you tighten will gall the two together!

The type of lockingnut can vary depending if the bolt is under tension or shear loading. Quite often a bolt loaded in shear only is only snug tight and tension load is a specific torque to achieve the required bolt stretch to keep the fastener from loosening. Classic example of this is engine headbolts or nuts and connecting rod nuts.

For high temperature applications mechanical locking, ( staked, piened, cotter pins, safety wired, lock tabs ) is necessary. For low temp applications ( nylocks, threadlocker, double nutting)

On aircraft there are castle nylocks, both nylon and a cotterpin, I have even seen on larger bolts where the bolt is hollow with a mechanical locking nut, then a smaller longer bolt goes thru the larger bolt with a large washer that keeps the large nut from coming off.

Of course Murphys law always rules!

Similar to Loctite, you can take a paint pen (or even fingernail polish) to dab on one side of a tightened bolt head, or to the nut/thread junction. It will make it a little harder to remove when dry, but very easy to note movement, loosening, or tampering.

aerotite stiff nuts have 2 very fine cuts in them at an angle.

we also have flange nuts and bolts that look like they have a serrated washer as part of them.

 

mostly I just use nylocs

for some things I use loctite blue

I have seen both nuts and bolts drilled and a wire attached as well as bolts drilled and Castle Nuts used.

Castle Nuts

 

 

Usually I have seen these with a cotter pin across the nut and through a hole in the bolt. The ends of the cotter pin are then opened so it can not pull back through the bolt

A bit of good torch work will remove a nut without damaging the screws on the bolt so have at it. <grin> It's a good demo when reporting to a new shop so's the guys know you walk the walk.

 

Frosty The Lucky.

Hub nut from a Ford, looks like it's made up of a bundle of washers that stretch apart to lock.

I've also seen it welded on the outside, that could be replicated at home..