Permanent thread lock

[bertterbo]

I need to permanently lock a nut to some M8 thread. There isn't enough room to weld it.

Out of Loctite 263 or JB weld (or something else?), which is going to give me the strongest connection?

I'll be using it on a motor shaft, that will rotate in both directions.

 

[Phil Pascoe]

CA adhesive.

 

[Chrispy]

Can you drill and pin it?

 

[Dee J]

https://www.techsil.co.uk/loctite-270-10mlLoctite 270 is nominally 'permanent'

 

[dizjasta]

 

[eribaMotters]

A castellated nut and split pin would be the old school 100% solution to the problem. I'd be happy with a nylock and a spot of loctite, just in case.

Colin

 

[bertterbo]

I can't use anything like that sadly. I need to use the original nut. Can't use a pin either.

Basically I am looking for a glue. Something that would make it very difficult to even undo the nut with a spanner.

 

[sams93]

I used loctite 638 for some bearings recently. Since then I’ve had a few occasions where I wanted to attach a nut to some threaded bar and used it to secure the nut.

I’ve been really surprised at just how good it’s been, copes with being tightened using an impact driver (not wrench) and socket.

Have put some serious force through that set up and haven’t actually let it set for more than about an hour before tightening each time. I’d be quite happy to use it again for future jobs, if I really was worried about the tightening force then I might actually let it cure for 24h or something.

 

[TRITON]

Leaving a bit of the thread proud of the nut then use a ball peen hammer to mushroom the end. It will not come off after that.

It's known as 'peening the pin'

 

[bertterbo]

I used loctite 638 for some bearings recently. Since then I’ve had a few occasions where I wanted to attach a nut to some threaded bar and used it to secure the nut.

I’ve been really surprised at just how good it’s been, copes with being tightened using an impact driver (not wrench) and socket.

Have put some serious force through that set up and haven’t actually let it set for more than about an hour before tightening each time. I’d be quite happy to use it again for future jobs, if I really was worried about the tightening force then I might actually let it cure for 24h or something.

There are so many types all saying permanent 263, 270, 638 etc

Edit: looks like 638 is a retaining compound which is supposed to form a stronger bond than thread lockers. Hmmmm

 

[Against_The_Grain]

Get into an argument about sharpening, locks up a thread tight as anything!

 

[sams93]

There are so many types all saying permanent 263, 270, 638 etc

Edit: looks like 638 is a retaining compound which is supposed to form a stronger bond than thread lockers. Hmmmm

I bought 638 as I was bonding a bearing with a gap of 0.10mm (might not be that as the figure is from memory) and the data sheet says it performs well in that situation.

Loctite publish all the data sheets so you can work out what’s best for your purpose

 

[quench]

Loctite structural is what I would use

 

[PDW125]

Loctite 638 is the one to use however you need to properly clean the threads and degrease before hand

 

[bertterbo]

I now have some 638 on order

In the mean time, I did some tests with CA glue and some threaded locker I found in the house. I believe its 871. Just securing a nut to some M8 thread.

After 12 hours to cure (probably needs 24 hrs) I was surprised by the results. The CA was actually harder to dismantle.

Hopefully the 638 will be better.

 

[sams93]

Honestly I have been astounded by the 638. The loctite brands are made by henkel, i'm not sure what the brand you have there is.

Will be interested to see your experience with the 638 when you get it.

 

[bertterbo]

Honestly I have been astounded by the 638. The loctite brands are made by henkel, i'm not sure what the brand you have there is.

Will be interested to see your experience with the 638 when you get it.

Yeah, if you search ebay for Loctite, 95% of the results are for what looks like a Chinese knockoff.



But I went with one of the Henkel ones

 

[sams93]

You don’t use much at all either, so it will probably last you a while

 

[bertterbo]

Well, the 638 arrived today. Applied it to a nut on an M8 bolt and gave it 24 hours to cure.

Was able to dismantle it with relative ease using two spanners

Maybe I'm not degreasing it thoroughly enough? what do you use to properly clean the threads?

 

[Tris]

If you can't drill through the nut can you drill down the nut? I'm thinking put the nut in place then drill down between nut and shaft, pop in a suitable diameter bit of rod to act like a keyway