Rounded out hex screw, removal help

[Saint Michael Arms]

Let me start by saying I am retarded.:D

I have a Midwest Industries two piece FF rail I'm trying to remove from an upper I've acquired. The hex screws on the trim ring are all rounded out. I don't know the history of the upper.

Midwest is sending me some replacement screws, but the originals are still stuck.

I tried some various tricks before they were totally rounded out, which in retrospect was a bad idea. The upper was left in a freezer for a few hours; that failed. I used a torch to no avail.

I tried dremeling a notch for a screw driver. That too failed - the metal on that screw head is just so soft.

I have some JB weld curing on a hex wrench I pounded in there to see if that works. I just have a feeling it will not. I just want the damn things out so I can put in the replacements and sell this damned piece of metal!

Ideas Gentlemen?:confused:

[dail621]

Try a screw extractor.

http://www.amazon.com/Smith-Wesson-SW1062-Extractor-5-Piece/dp/B000M64SDM

[cymax]

hello i went on the midwest industries web site and looked at how the rail is made... i would try to weld another bolt on top with a tig if possible and use the welded bolt to unscrew.

another method would be to slowly with dremel the top of the screw out remove rail and use the stub of the screw and vice grips or weld a bolt to the stub

a pic of the screws would be nice if possible and may generate more ideas

[Saint Michael Arms]

I'll get some pictures up soon, but that JB weld is curing and I don't want to mess with at the moment.

[macman37]

Use a punch and hammer. Put a dimple on the face, next to the stripped hole, on the right side of the bolt.

Then turn the punch at an angle in the dimple and tap it up (lefty loosey).

Tough to describe. It's worked for me twice now.

Also consider, if the bolt is proud and you can get a Dremel in there, grinding a slot and use a screwdriver to turn it out.

In both cases flood the screw with Kroil.

[Black Jeep]

I run into this on my bike all the time except with damn Torx head bolts. Since you're waiting on the JB weld to cure then let that process work. You need the right tools to do the job, which in this case are an impact screwdriver and a vice, but that ship may have sailed.

Here's what I do when I get stuck in this situation and I don't have an impact screwdriver:

1. Soak the offending screw in your favorite solvent (ala WD-40) and let it set a bit
2. Use a NEW wrench - their sharper edges bite better
3. Use a the metric or SAE size that is slightly larger and tap that into place with a hammer and turn while tapping

Don't get into too much of a hurry. Cutting a notch w/ the dremel or even JB welding a wrench into the bolt is a last resort for me b/c all other attempts have made using the proper tools impossible and now I have to improvise.

Can you tell I've done this before? I may not know much about M-4's, but I know a bit about screwing around in the garage.

[Hoss356]

I second the screw extractor, I used to have the master extractor set from Irwin and it served me well in situations like yours. Just think of this as a great excuse to buy more tools!

[ucrt]

Get the proper size left-handed drill bit.

The proper size is a tad smaller than the screw body. After Kroiling it for a few hours, center punch a spot to start drilling.

Drill away. Most of the time, they unscrew pretty quick. I have had difficult screws stay in until you get the drill point just below the bottom of the head into the screw's body and then they come out.

Kroiling is important.

Left-handed bits are very handy, fast and easy.

.

[EzGoingKev]

3. Use a the metric or SAE size that is slightly larger and tap that into place with a hammer and turn while tapping

95% of the time you can hammer in a slightly larger torx bit and turn it right out.

It is has been loctited then you might have to put some heat to it also.

[Saint Michael Arms]

I'll swing by the store and get some screw extractors in the morning. I'm going to let the JB weld sit tonight.

Former owner emailed me and said he used red loctite on them, since they were almost rounded out - he didn't want them backing out.:(

I suspect my propane torch didn't heat them up to 500 degrees.

Talk about a learning curve. Better to mess up stuff I own, than someone elses I suppose:laugh:

I will keep you gents updated on the hex screw hostage situation.

[Saint Michael Arms]

Of course the JB weld failed. I didn't seen any screw extractors small enough at the local hardware store; I've ordered some of those S&W screw extractors.

Pictures of my stupidity:D

http://img522.imageshack.us/img522/1620/strippedscrew2.th.jpg (http://img522.imageshack.us/i/strippedscrew2.jpg/)
You can see some left over JB weld residue.

http://img827.imageshack.us/img827/7228/strippedscrew1.th.jpg (http://img827.imageshack.us/i/strippedscrew1.jpg/)

[Complication]

One tactic I've resorted to when all else fails is drilling out the screw/bolt. It's definitely not an ideal solution and it's really easy to damage stuff but you take a titanium (or something pretty hefty) drillbit just BARELY smaller than the body of the bolt itself, and slowly drill through the center of the bolt head.

Basically you slowly and carefully drill through the head until you hit the body of the screw/bolt and you end up drilling it out to the point where a fraction of a mm of steel is holding everything else together and you can just pop it all apart pretty easily. Then the rest of the bolt is usually ragged enough that you can a) use a pair of pliers to unscrew it or b) use a screw-removal bit to get it out.

It should go without saying that this is WAY WAY down on the list of things you should try and, if attempted, should be done with extreme patience and care, but I've had to do it a few times over the years and it's always worked (and always been nerve-wracking). You also get metal shavings everywhere so be careful.

Good luck.

[ucrt]

Use pretty much the same guidelines that "Complication" recommends to drill out the screw BUT use a "left-hand drill bit". While you are drilling the screw with a "left-hand drill bit" it is "torquing" the screw in the direction that it needs to unscrew.

I have used and have seen L-HDB used dozens of times down to #8 screws up to 1/2" and have rarely seen a screw have to be completely drilled out. Most of the time the screw generally comes unscrewed real quick and for that reason, we use a L-HDB first off. If we need an extractor, we've already got a hole the L-HDB drilled for it.

One source: McMaster-Carr (http://www.mcmaster.com/#left-hand-drill-bits/=92qmgl)

But maybe it's just me...
.

[SW-Shooter]

Find an appropriately sized flat tip screwdriver and use that to remove it. Generally it will grab the screw if you use the right tip size.

[MistWolf]

The very last thing you should try when removing screws or anything else on an AR is an open flame from a propane torch. The receivers, both upper & lower are heat treated aluminum. The temperatures from the torch can anneal that aluminum QUICK. The heat from a heat gun applied at too high a temp or for too long will also ruin the heat treat. The other danger is that the open flame can cause carburizing. This is the introduction of carbon from the open flame into the metal which in turn causes embrittlement.

The first thing you want to do when removing stubborn hex head bolts (after soaking in Kroil, Mouse Milk or Winter Green. You can use WD40, but it doesn't work near as good as the others) is to grind back your Allen key until you have a flat bottom and sharp sides. This will give you the best bite. If you can, get the Allen key bits that fit into 1/4 drive screwdriver handle (called Apex bits). Insert the Apex bit into the screw head and tap it with a hammer while turning the bit. Be careful, you can turn too hard and finish stripping the head.

It takes a bit of feel to do this. You want to feel the bit biting into the recess.

Some use a impact wrench for this and they can work. The trouble is the wrench is spring loaded. The taps from the hammer are softened. It often take the sharp shock from the blow to get the crapola loosened and stubborn threads to kinda jump so they'll let go.

If, as a last resort, you MUST use the EZ Outs (screw extractors) BE EXTREMELY CAUTIOUS!! I cannot emphasize this enough! BE EXTREMELY CAUTIOUS!! EZ Outs are made of very hard material so they'll bite into the screw. They break very easily, especially the smaller diameter ones. When one breaks off in a screw, unless you can dig out the pieces, you are done. The part left in the screw will be impossible to drill out. The drill bit will wander off of it and possibly damage the surrounding area. Sometimes an EZ Out will remove three of four screws with no problem and break on the next.

When using EZ Outs, employ a tap handle. This will reduce the possibility of applying side pressure and snapping the extractor. You can tap on this setup with a hammer, but don't over-do it.

When drilling the screws for the EZ Outs, use a drill smaller than the minor diameter of the threads. You need metal for the EZ Outs to bite into.

If you drill the heads off, drill just deep enough to snap the heads off with a pin punch. This MAY leave you enough of a stub above the material, once you get the part off, to grip with a pair of Vise Grips brand locking plier and spin it out. Note that I said Vise Grips brand locking pliers. I have yet to find a pair of knock off locking pliers that works as well as genuine Vise Grips for this kind of work

[MistWolf]

PS- As stated in previous posts, left handed drill bits and a reversible drill motor is your friend

[MistWolf]

What is that screw going into? Are there threads sticking out the other side?

[Jimgto67]

Believe it or not after you drill a little bit to allow use of a screw extracter, use a soldering iron on the bottom of the screw if you can get to it while trying to untorque the screw. This will localize the heat transfer and minimize any adverse effects to surrounding metal.

[Saint Michael Arms]

This is outstanding advice gentlemen. I'm waiting on my screw extractors, and calming my chi (amazing how a piece of metal can piss you off). While marred, my current plan is to see if screw extractors can bit into the screw heads.

Based off the design I can access the bottom of the screw holes, perhaps hit those area with a torch, leaving the crew heads cool enough to get bit by extractors?

At this point it is a learning exercise, screw the hundred or one fifty I'd get forthe rail.

I really appreciate you all's advice; will update.

[MistWolf]

If the screws are long enough to have threads sticking out the bottom, drill the heads off and grip the exposed threads with Vise Grips and spin them out. Spin them in the direction that you would go if inserting the screws deeper. The marks on the threads from the Vise Grips will more likely damage the threads of the parts than the threads where the heads were drilled off

[rat31465]

I had a Torx Head strip on me and I used a Square headed mag bit to remove it. A S1 works on alot of the smaller sizes...tap it in place with a lighter hammer and turn it out while applying downward pressure to it.

[Boothj]

A set of these should get the job done it's what we use at the shop to remove those pesky stripped out heads on grip screws.

http://www.google.com/products/catalog?hl=en&rls=com.microsoft:en-us:IE-SearchBox&rlz=1I7GGLL_en&q=grabit&revid=314088557&wrapid=tlif12860284003312&um=1&ie=UTF-8&cid=6971677141023281343&ei=hjynTMrON4GglAfjg83IDQ&sa=X&oi=product_catalog_result&ct=result&resnum=5&ved=0CDUQ8wIwBA#

[Schulze]

I had the same problem with my MI 2 piece. :rolleyes:

[Suwannee Tim]

This is no help for St Michael Arms but for reference:

The best way to deal with a stripped socket head cap screw (SHCS) is not to strip it. SHCS are very prone to being stripped as the hex is so small, smaller than the threaded shank. If you are screwing on a fastener that might strip you want to be very cautious. Use a good hex key with a sharp end, not chamfered and with flats that have not been rounded, a high quality, hard steel hex key, not some soft, cheap import. If it is plated, not black oxide it is probably soft and cheap. Make sure the hex key fits, make sure you are not doing something like trying to use a metric key in an inch fastener or such. Make sure it is in fact hex and not Torx or square, small fasteners can be deceiving, use a lens to inspect it if it doesn't seem to fit. If it doesn't seem to fit, stop and figure out why. If the hex key is not sharp, you can dress it down with a grinder. If you can cut it easily with a file it is not hard enough. Stainless SHCS are softer than black oxide, if you need to torque it, substitute black oxide. If they corrode, replace them. Use Hol-krome brand fasteners. SHCS are cheap, when in doubt, chuck the suspect fastener and replace it. When you install a screw make sure the threads are clean and lubed. I take much care not to strip a SHCS.

McMaster (http://www.mcmaster.com/#socket-head-cap-screws/=93uowe) is a good source for quality fasteners as well as many other things.

[Thomas M-4]

If all else fells just find a welder and weld the key to the socket.

[Suwannee Tim]

If all else fells just find a welder and weld the key to the socket.

I think you have no idea how difficult it is to do such a thing without ruining the underlying metal. The one sure fire way to remove a broken screw is to have it EDM machined out. Expensive.

[Thomas M-4]

I think you have no idea how difficult it is to do such a thing without ruining the underlying metal. The one sure fire way to remove a broken screw is to have it EDM machined out. Expensive.

If you read my post in its entirety you will see that I said if all else fails:big_boss:

And no it's not that difficult if you know how to weld.


Add
Stick or mig would most likely be unacceptable but a good tig welder should a good chance of getting an acceptable weld. Depending how much is left to work with.

[Thomas M-4]

I think you have no idea how difficult it is to do such a thing without ruining the underlying metal. The one sure fire way to remove a broken screw is to have it EDM machined out. Expensive.

Himmm I fig there was a reason for the post.


Join Date: Aug 2010
Location: North Florida


ROLL TIDE ROLL

[DBR]

There is some good info here regarding mechanical ways to remove a stuck fastener.

I have used Allen type screws in critical design applications. There is a reason "real" Allen type fasteners and wrenches cost more than the hardware store variety.

Real industrial quality Allen wrench brands like Unbrako, Allen, SPS and others I am not familiar with are designed to shear off (not round) at the screw head before they damage the screw. This of course assumes they are working with spec grade 5 or grade 8 screws and no Loctite. The first sign of an out of spec fastener or wrench is if there is noticeable play between the wrench and the screw head. The wrench should be a tight fit in the screw.

If 271 (red) Loctite has been used heat must be used before attempting to loosen the fastener. IMHO "Liquid Wrench" is one of the better penetrates to help soften Loctite.

As others have said, a heat gun (or maybe a hair dryer) is the best way to soften Loctite with the least risk of damaging the part. If the Loctite is defeated and the screw is not galled anything that fits tightly in the head should be able to remove it. I favor using a wrench that fits the head and tapping it into the head while turning. This is most effective with a straight type insert in a handle.

[Suwannee Tim]

And no it's not that difficult if you know how to weld

I do know how to weld and here are some of the problems:

There is no root to fill between the screw and the key, where are you going to put the weld metal? The arc is as likely to jump to the aluminum as the steel screw. The balance between enough heat to achieve fusion and to much which melts through the fastener would be very difficult or impossible to hit, especially without something to practice on. If you melt the screw the aluminum will be immediately ruined. At low heat you will transfer most to the heat to the aluminum and at high heat things will melt so fast you won't have time to react. No matter what you will transfer a lot of heat to the aluminum which will likely soften it. The welding current will necessarily flow through the screw and into the aluminum and cause an electrochemical reaction which seizes the screw shank into the aluminum. I can think of more but I have made my point. I think if you knew how to weld you would know that this idea is impractical at best and impossible at worst.

[Thomas M-4]

Never mind I saw the pic I was mistaken I thought it was a cap screw.
I would try a screw extractor.

[Suwannee Tim]

Its called TIG it gives you more control on your weld puddle that is what the foot pedal on the thing is for to give you instant control on you puddle you can also adjust the width and depth of the penetration.

Tig puts more heat into the base metal than any other commonly used process, just what you don't want.

[Thomas M-4]

Tig puts more heat into the base metal than any other commonly used process, just what you don't want.

Man last night the pics didnt load I thought it was a cap screw but it not.
My bad on that. Welding will not work on this application.

But you can say what ever I have welded sockets and key's and seen a half million mechanics do the same with out problems.

[VooDoo6Actual]

Easy day,

Drill pilot hole and use appropriate size "EASY OUT"....

HTH.....

[jklaughrey]

Hop, you beat me to it. Easy Out is always a good call.

[MistWolf]

As long as the EZ out doesn't break