View Full Version : staked castle nut vs lock-tight?
I've got a couple of ARs where I use locktight on the buffer tube and castle nut. I haven't had any real problem with this, and My ARs see some fairly hard use.
I'm getting ready to put together another lower and was revisiting this.
Is staking the castle nut a must do, as opposed to lock-tight?
Which is easier to get off if you have to?
I've got a couple of ARs where I use locktight on the buffer tube and castle nut. I haven't had any real problem with this, and My ARs see some fairly hard use.
I'm getting ready to put together another lower and was revisiting this.
Is staking the castle nut a must do, as opposed to lock-tight?
Which is easier to get off if you have to?
Definately stake your castle nut. Loctite can be problematic when trying to remove the castle nut because at times you have to apply heat to the receiver extention which can damage and weaken it. Loctite is the quick corner-cutting way imo.
I have removed a few that were staked, but have not removed any castle nuts secured with Loctite. However, I have removed a good number of other things that were secured with (probably too much) Loctite, I'd go with staking. It's secure under use, but not too hard to remove if you need to do so. IMO/IME, of course.
OP, just stake them. They will be fine. Loctite could be used but staking is tried and true.
ETA: I have had 2 back off on me that were not staked.
SomeOtherGuy
10-30-12, 18:45
Staking is the way to go, and very easy to do with an automatic center punch. And you can partially undo the staking with the same punch, and then undo the nut with a wrench without much difficulty.
Definately stake your castle nut. Loctite can be problematic when trying to remove the castle nut because you have to apply heat to the receiver extention which can damage and weaken it. Loctite is the quick corner-cutting way imo.
you do realize that you dont need to apply heat to all loctite products? blue is different than red.
OP, just stake them. They will be fine. Loctite could be used but staking is tried and true.
ETA: I have had 2 back off on me that were not staked.
Thinking back on it a couple years ago i had a rra that had the castle nut come loose, and iirc they use loctite.
you do realize that you dont need to apply heat to all loctite products? blue is different than red.
I have seen situations with both red and blue that do require heat to remove, not as common with blue.
Suwannee Tim
10-30-12, 19:53
I did quite a bit of tinkering and messing around with this, I found that a castle nut socked down tight without thread locker or staking will hold for several months of moderate use. A little bit of Loctite and the castle nut socked down tight and the nut is much harder to remove. As hard or harder than staked. From this I conclude my method is adequate. I use blue or purple Loctite, I run the nut down hand tight then back it off 1/16 of a turn. I apply one drop in one of the castleations then sock it down. To repeat the removal torque is approximately the same as staked which is a good bit harder than tightened only. Removal is no big deal and it's completely reversible which is why I am doing it this way. It's a little known fact that locking a nut does not take a huge effort. For example, the nuts on a big steam turbine can be locked with nothing more than a Palnut. I asked several of GE's experts about this and was universally assured that it was more than adequate, even for that very demanding application.
From a reliability perspective, mechanical securing of critical fasteners is preferred if not prevented by other issues ie can't physically access the fastener. Increased robustness and reliability is the reason we specify use of safety wire on many fasteners in aviation. If the fastener comes out and jams up something critical downing the plane, everybody has a bad day..
Another advantage of staking is the ability to notice if the castle nut has shown any sign of failure based on location of the stake mark on the end plate not being lined up properly with the notch on the castle nut.
I would just stake it and be done with it, so you don't have to worry about it.
Proper installation is to install the receiver extension in the lower receiver, torque the receiver extension nut to spec, then stake the receiver end plate.
No loctite needed. Torque to proper spec and stake correctly.
Carbine 38-42 ftlbs
Rifle 35-39 ftlbs
I have yet to see a sever or hard use rifle fail with a proper installation in this preferred method.
scoutchris
10-31-12, 09:08
The heat you would need to apply would not be sufficient enough to change the composition of the metal, therefore would not "weaken" it. Do whatever floats your boat.
I've had to remove a bushmaster locktite job, I hope to never have to do it again.
Now I remember I have to get the gas block off of my .450 to change the tube handguard I hate since the ar gunsmith said he gave up because he was afraid he was going to tear up the barrel, oh well.
Just say no to loctite when it's not needed.
Mig weld it in place.
Would be easier to remove than bushmaster's locktite.
Mig weld it in place.
To funny for words!!!:lol: Stake it no doubt!
I would just reinvent the wheel.
No loctite needed. Torque to proper spec and stake correctly.
Carbine 38-42 ftlbs
Rifle 35-39 ftlbs
I have yet to see a sever or hard use rifle fail with a proper installation in this preferred method.
This is the by the book answer. Truthfully, the correct application of thread locker and correct tq would probably be fine and may be preferred if you fiddle with the re often.
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This is the by the book answer. Truthfully, the correct application of thread locker and correct tq would probably be fine and may be preferred if you fiddle with the re often.
If you're fiddling with the RE that often, you need to be punched in the nutsack.
I was just made aware that the RE needs to be torqued to spec.
The only thing I have is the basic spanner wrench and I tightened the nut until I couldn't any more. I haven't staked it as I don't have the means for that and will do so when convenient. But is it bad to merely tighten the RE as much as possible?
This isn't rocket science, why try to reinvent the wheel? Why would you "need" to remove and reinstall the RE? As an armorer at a department that issues mostly Bushmaster I have had occasion to remove several with loc tite and always hate it.
ClearedHot
11-01-12, 02:03
There must be a reason why the TDP calls for staking and not Loctite...
Suwannee Tim
11-01-12, 04:36
.....Why would you "need" to remove and reinstall the RE? As an armorer at a department that issues mostly Bushmaster I have had occasion to remove several with loc tite and always hate it.
In my case I had five lowers and one parts kit including one RE, one nut and one end plate. I wanted to SBR two lowers, assemble one and stash two but I wanted to prove every one. I assembled them, each in turn then shot a thousand rounds. The reason I used Loctite is that it is completely reversible. I only used one drop of Loctite in one castle nut slot and it bound the nut up good and tight but not so severely that removal was a problem. I removed the nut without heat, just a good hard pull on the wrench. I'm not proposing Loctite as a substitute for staking. My point is that properly applied it works, is removable and in some cases is appropriate.
Another reason to keep the RE removable, I was experimenting with sling mounts and a couple of them were end plate mounts. It was very convenient to have the Loctite versus staking.
The Loctite worked so well in these experiments I feel no particular need to go back and stake the one gun I have that Loctited presently and I will probably use Loctite on the SBRs when my documents come in.
Then again, I am not a soldier, Marine or cop. A failure is no big deal, I carry my tools to the range and would just tighten the nut back up though I would be very surprised to see one come apart. I am confident that it will never happen.
I did use just one drop of Loctite. I have never removed a Bushie castle nut but I can well imagine that with much more than one drop of Loctite it would be a real challenge.
I have disassembled things that were Loctited which required a lot of heat and a lot of force and produced a lot of stinky acrid smoke and a lot of foul language.
Suwannee Tim
11-01-12, 05:41
There must be a reason why the TDP calls for staking and not Loctite...
One very good reason is the AR10 was developed in 1954-55 and Loctite was introduced in 1956. If the timing had been different it is entirely possible that the established and accepted method of locking a castle nut would be one drop of Loctite. Then we would be arguing whether two drops was better than one, whether purple, red or blue was best. Then some lunatic would come along and propose staking, causing a general uproar.
If the OP is asking if loctite will hold sufficiently, I would say yes. I have seen it hold fasteners that see a lot more stress. As to what is better, one would have to define better for what. I would say use what ever suits you best. Obviously the way it is "supposed to be done" is staking.
Suwannee Tim
11-01-12, 06:10
Another thing I did in assembling the five lowers was to use a Cotter pin on the bolt latch, 1/8" by 1" IIRC. Much easier to get in and out than a roll pin. I used a 1/4" x 1-1/8" shoulder bolt for the front take down pin and used a Cotter pin instead of roll pin on the trigger guard. I will of course use standard components when I permanently assemble these lowers.
One very good reason is the AR10 was developed in 1954-55 and Loctite was introduced in 1956. If the timing had been different it is entirely possible that the established and accepted method of locking a castle nut would be one drop of Loctite. Then we would be arguing whether two drops was better than one, whether purple, red or blue was best. Then some lunatic would come along and propose staking, causing a general uproar.
That last line is funny. I don't care who you are. :D
Staking all the way. Why bother with Loctite? It's just a pain in the ass. A good staking job offers superior durability and at the same time, it's just as easy or easier to remove.
I think I've seen an SR-15 with Loctite on the castle nut, however. Makes you wonder what the guys at KAC were/are smoking. :confused:
nineteenkilo
11-01-12, 08:20
I have no problem with Loctite myself and use it in many applications. Having said that, how hard is it to buy and use an automatic center punch?
It's 5 bucks, a retarded rainbow monkey can use it properly, and it gives peace of mind.
midSCarolina
11-01-12, 10:48
When swapped out the factory plate for a single point sling mount, I just tightened the castle nut down and didn't use loctite or anything. I have put about 1200 rounds through it since then and it has held up really well. I did mark it so I know if it is starting to slip, but I do that with every peice of gear that can rotate. I have done this on 3 rifles and have never had an issue but if you don't plan on ever changing it out, staking it would be good.
When swapped out the factory plate for a single point sling mount, I just tightened the castle nut down and didn't use loctite or anything. I have put about 1200 rounds through it since then and it has held up really well. I did mark it so I know if it is starting to slip, but I do that with every peice of gear that can rotate. I have done this on 3 rifles and have never had an issue but if you don't plan on ever changing it out, staking it would be good.
It's possible that a castle nut can stay in place with nothing... not worth the risk to me...
And Staking isn't permanently attaching or commiting. You can break and restake any time you want. That's why I put light stakes. You don't need as much as a automatic centerpunch gives you.
nineteenkilo
11-01-12, 13:10
Double post
nineteenkilo
11-01-12, 13:11
You don't need as much as a automatic centerpunch gives you.
That was simply for those too stupid/lazy to use a hammer and punch/screwdriver. :jester:
Maybe it would be worth moving to $10 for an adjustable model.:D
Centerpunch works fine.... don't get me wrong... It's just that you can get away with a light staking. You're only stopping the part from vibrating loose.
One very good reason is the AR10 was developed in 1954-55 and Loctite was introduced in 1956. If the timing had been different it is entirely possible that the established and accepted method of locking a castle nut would be one drop of Loctite. Then we would be arguing whether two drops was better than one, whether purple, red or blue was best. Then some lunatic would come along and propose staking, causing a general uproar.
This is hilarious because it's plausibly true. :D
It's possible that a castle nut can stay in place with nothing... not worth the risk to me...
Any properly torqued fastener should stay in place with no other additions or changes. Notice the word should again.
There are a million and one instances where things just don't work like they "should" for whatever reason. People need to think of staking as functional insurance for their rifle. It's there to cover all the variables that you can't account for, and make sure that your rifle works when you need and want it to.
Think of it this way, can you drive your car around without insurance? Yeah. Is it a good idea? Nope.
In the same line, can you fire your rifle without staking. Sure enough. Is it a good idea? Again, not in the least.
Suwannee Tim
11-01-12, 16:54
An unstaked unLoctited castle nut will work loose. This is true of almost all ordinary screws and bolts subjected to significant vibration. This is why you find virtually all fasteners on a car or truck have some method of self locking. It may be tooth like serrations under the head, a nut that has been squished to bind the screw, a screw with a triangular cross section, Loctite, et cetera, et cetera. I encourage you to continue with your unlocked castle nut and let us know if, when it comes loose. The one I tried lasted about a thousand rounds, longer than I expected.
I can remember back in the days when carbines were getting popular and collapsible stocks were becoming popular. Many of the guys at the various gun clubs and ranges all carried a high speed spanner wrench in their back pocket. Nobody staked then and hardly anybody used loc tite but those wrenches sure stayed busy!:o
DeltaSierra
11-01-12, 21:18
When swapped out the factory plate for a single point sling mount, I just tightened the castle nut down and didn't use loctite or anything. I have put about 1200 rounds through it since then and it has held up really well. I did mark it so I know if it is starting to slip, but I do that with every peice of gear that can rotate. I have done this on 3 rifles and have never had an issue but if you don't plan on ever changing it out, staking it would be good.
Super. Glad that whole 1200 rounds proved to you that you don't need to stake the castle nut....
You say you "put" 1200 rounds through it? Cool. How much have you carried the rifle? How many miles has it bounced around in a vehicle beside you?
Putting rounds through a rifle isn't the only measure of its durability. Sometimes actually carrying the thing is gonna be harder on it than going to the range and shooting - amazing, I know....
nineteenkilo
11-01-12, 21:47
As a very relevant addition to this thread, I just pulled a factory castle nut off of a brand new BCM lower. It was properly staked and very clean (as usual with any BCM product). It was a screaming blue mother****er to get off. I bent the first small stock wrench and had to use a pin punch to break the staking.
Well done Bravo Company!
I did have a moment of concern as it appears one full thread round is galled and fell out with the tube removal. Doesn't matter in the long run, but worth noting.
Put the lower together last night. Function test is fine, I will test fire it and stake it tomorrow.
I staked my primary just because- now it's stake AND lock-tighter. Hope I never have to take it off.
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