vic008
Active member
For say half inch bolt. Thanks
Most effective locking washer?
- Thread starter vic008
- Start date
Concerto
Well-known member
Unless you are wanting to keep the height of the bolt to a minimum, I would always suggest using a locking nut rather than any washer.
MontyMariner
Well-known member
I've found Nyloc nuts work well.
Concerto
Well-known member
They are OK, but all keel bolts use a locking nut. Why? It is the most secure way to put pressure on the bolt thread to stop a nut coming undone.
wonkywinch
Well-known member
Slotted or castellated nut?
MontyMariner
Well-known member
I don't disagree, I use double nuts on my engine mounts, the second one is a Nyloc
john_morris_uk
Well-known member
Lots of myths about locknuts. Try this article:The Use of Two Nuts to Prevent Self Loosening of Fasteners
john_morris_uk
Well-known member
And in case you put your money on locking washers Helical Spring Washers.
Daydream believer
Well-known member
Loctite. But check the grade first as there are many applications.
but as suggested above. Can one really beat a castellated nut?
even gives a degree of visual indication of possible failure
but as suggested above. Can one really beat a castellated nut?
even gives a degree of visual indication of possible failure
Neeves
Well-known member
We need to know the application.
But check the specification of the Loctites.
I used, a rather generous amount of red Loctite on an inter screw and needed a blow torch to release. I had used grossly oversized shifters, to increase the length of the lever, without success. Heat is the answer -but often you cannot use heat.
Loctite can be applied and used not cured under water. Loctite sets off with moisture and will set under water. You need to be careful that the Loctite is not washed off before you apply - but both, specific grades of, red and blue work surprisingly well
Hardly exhaustive - but indicative
Adhesives Test - Practical Sailor
A castellated nut with cotter pin would be 'secure' but would still allow the nut to loosen unless the cotter pin is in exactly in the right location - which seems unlikely.
The thought of loose nuts on keel bolts or an engine mount is something of a night mare.
Jonathan
We don't know the application but simplistically use red Loctite for a permanent fixture and blue for one where there will be regular need to release (and in the latter case use fresh Loctite for each release).
But check the specification of the Loctites.
I used, a rather generous amount of red Loctite on an inter screw and needed a blow torch to release. I had used grossly oversized shifters, to increase the length of the lever, without success. Heat is the answer -but often you cannot use heat.
Loctite can be applied and used not cured under water. Loctite sets off with moisture and will set under water. You need to be careful that the Loctite is not washed off before you apply - but both, specific grades of, red and blue work surprisingly well
Hardly exhaustive - but indicative
Adhesives Test - Practical Sailor
A castellated nut with cotter pin would be 'secure' but would still allow the nut to loosen unless the cotter pin is in exactly in the right location - which seems unlikely.
The thought of loose nuts on keel bolts or an engine mount is something of a night mare.
Jonathan
Refueler
Well-known member
AS most nut / bolt use has washers as well .... then
may be a bit questionable as it gives impression of no washer ? I agree that best is a locking nut of some description ...
But tab washers ... star washers .... serrated washers ... they all work ..
Maybe a combo of locking washer and a locking nut ??
Some mention Loctite / threadlock - personally I am not a great fan of such on a boat unless its only solution such as when thin nut on short bolt. I much prefer a mechanical solution.
may be a bit questionable as it gives impression of no washer ? I agree that best is a locking nut of some description ...
But tab washers ... star washers .... serrated washers ... they all work ..
Maybe a combo of locking washer and a locking nut ??
Some mention Loctite / threadlock - personally I am not a great fan of such on a boat unless its only solution such as when thin nut on short bolt. I much prefer a mechanical solution.
wallacebob
Active member
And there’s the good old Binx nut, low profile , reusable.
RunAgroundHard
Well-known member
Assuming no nut:-
Nordloc style wedge lock washers.
Thread locking compound
Selflock thread profile if the hole has still to be tapped
Lock wire to another bolt if part of tge same assembly.
Assuming a nut:-
Palnut (stainless)
Thread locking fluid.
Thread deforming Metal Lock Nuts. They are single use, metal, similar to Nyloc but with a deforming metal thread.
I would use a thread locking compound, very reliable in many environments.
Neeves
Well-known member
Volvo provide their version of a blue Loctite, maybe Loctite with a Volvo label, and a tab washer for the securement of their 3 bladed folding prop. Their folding props are significantly expensive.
On a smaller scale Gori use a tesselated nut and cotter pin for their 2 bladed folding props.
Jonathan
Sandro
Active member
In the very interesting articles suggested by john_morris_uk, I was impressed by the lack of reliability of the locking helical spring washers ("Grover washers" as as we call them), in which I trusted life long.
My idea was that, when vibration causes a momentarily gap under the nut thus freeing it, expanding of the washer keeps the preload and prevents rotation. Moreover, the sharp edges of the splitted washer would cut a sawtooth dent in the working faces of nut and piece, preventing rotation in the undoing direction.
But one must give up to experimental evidence.
About locking nuts, as Refueler, i like better iron than plastic, but they are useful in applications where the bolt works as hinge and is inherently loose.
My idea was that, when vibration causes a momentarily gap under the nut thus freeing it, expanding of the washer keeps the preload and prevents rotation. Moreover, the sharp edges of the splitted washer would cut a sawtooth dent in the working faces of nut and piece, preventing rotation in the undoing direction.
But one must give up to experimental evidence.
About locking nuts, as Refueler, i like better iron than plastic, but they are useful in applications where the bolt works as hinge and is inherently loose.
Poignard
Well-known member
What is this 1/2" bolt part of?
If it is part of, say, an engine then I would use whatever its designer chose to use.
I can't see any point in over-engineering something.
If a spring washer and plain nut will do why faff around with Nylocs, Aerotights, Loctite etc.?
As somebody (Neville Shute?) once remarked: "An engineer is a man (or woman nowadays) who can do for a shilling what any fool can do for a pound," (Or something like that
)
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vyv_cox
Well-known member
The quote, in Nevil Shute's Trustee from the Toolroom, is: "An engineer is a man who can do for five bob what any bloody fool can do for a quid". But he also says - origin unknown, so presumably he did not coin itAs somebody (Neville Shute?) once remarked: "An engineer is a man (or woman nowadays) who can do for a shilling what any fool can do for a pound," (Or something like that
38mess
Well-known member
On my 16mm engine mount studs I use half nuts on top of the standard nuts. Rock solid locked off
john_morris_uk
Well-known member
That’s how I’d always done it until I read the article I quoted earlier. Half nut first is demonstrably even more secure.
B27
Well-known member
Varies hugely with the context.
Why is the nut prone to loosening?
Is the problem vibration? Thermal effects? Plasticity of one of the components?
If you understand why a plain washer and full nut will fail in that circumstance, you might see what will work.
There's only one thing which will never, ever come undone, that's a corroded bolt on a French car.
Why is the nut prone to loosening?
Is the problem vibration? Thermal effects? Plasticity of one of the components?
If you understand why a plain washer and full nut will fail in that circumstance, you might see what will work.
There's only one thing which will never, ever come undone, that's a corroded bolt on a French car.
