I was trying to take the gas block off my AR and the bit broke in the "hole," or whatever the technical name is. It's essentially an allen wrench bolt. I was using a cheap Walmart bit, so I'm sure it's not hardened, but it's in there really good and I can't get it out.

My first thought was to drill out the center of the broken bit, hoping it breaks apart, but I've broken 4 bits doing that already.

I assume it's something like this, with a drill bit stuck in the hole:

Any ideas?

TIA.

Before offering any help just want make sure I'm understanding all. So it sounds like you broke the Allen wrench off in the fastener and you can't get it out….so you've tried to drill the broken Allen wrench part out with twist drill bits but they keep breaking off. Is that about it?

Gunny456 said:

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Before offering any help just want make sure I'm understanding all. So it sounds like you broke the Allen wrench off in the fastener and you can't get it out….so you've tried to drill the broken Allen wrench part out with twist drill bits but they keep breaking off. Is that about it?

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Yes, you are correct.

Going to take a drill press or mill. Going to need a new gas block when done. Not an expensive part anyway. Just don't drill too far….ie add a gas port where not needed.

I've used a dremel with a carbide or diamond grinding bit to grind the broken kit end off and make a bit of a center hole, then high quality left handed bits to drill out the plug center out until it's almost to the threads from the inside and then back it out

Thanks everyone. I figured I'd need a drill press and a new gas block. Appreciate the help!

If you are anywhere near The Woodlands I have a drill press you can use.

The Sun said:

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If you are anywhere near The Woodlands I have a drill press you can use.

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I am. I think my buddy down the street has one but if not I'll let you know. Thank you!

Not that it matters, but curious for my own learning....were you using an impact driver bit or a manual wrench?

35chililights said:

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This is the way. Never done this on a gun but have done it on a similar part. It works well.

Kyle Field Shade Chaser said:

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35chililights said:

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This is the way. Never done this on a gun but have done it on a similar part. It works well.

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Left hand drill bits work really well too

Don't need a mill or drill press. A vice and hand drill will work fine. Have a whiskey first. Use a left handed bit if you have one. Not an easy out, a regular drill bit that's left handed or backwards or whatever. Sometimes they catch and spin the screw out, sometimes they just drill in.

Drill the broken tool out. Tap a torx bit into the hole with a hammer and unscrew it like that. Heat the hole in the fastener up first with a soldering iron if you suspect thread locker. Keep drilling if that doesn't work.

If it's a broken Allen wrench as you say …..it slid into the female part to begin with before it broke. I have had the same issue on Allen head fasteners that broke wrenches on marine applications.
I was shown two tips that worked:
One ….. get as high a pressure air hose with as small a nozzle as you can and blow the high pressure air on the edge of the broke wrench part and the fastener. Make sure you wear gloves and safety glasses. If you can get the air under it…it will actually blow the part out.
2nd…..See if you can find a very strong magnet and as you blow the high pressure air .. place the magnet against the broke part and see if the magnet will help dislodge/pull it out.
Being that you have already tried to drill it out the above may not work as the drill bit may have lodged the broken piece in the fastener worse.
I know these methods may sound crazy but I have seen it work. If it works it saves you from having to ruin your fastener.

HalifaxAg said:

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Not that it matters, but curious for my own learning....were you using an impact driver bit or a manual wrench?

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Manual.

Gunny456 said:

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If it's a broken Allen wrench as you say …..it slid into the female part to begin with before it broke. I have had the same issue on Allen head fasteners that broke wrenches on marine applications.
I was shown two tips that worked:
One ….. get as high a pressure air hose with as small a nozzle as you can and blow the high pressure air on the edge of the broke wrench part and the fastener. Make sure you wear gloves and safety glasses. If you can get the air under it…it will actually blow the part out.
2nd…..See if you can find a very strong magnet and as you blow the high pressure air .. place the magnet against the broke part and see if the magnet will help dislodge/pull it out.
Being that you have already tried to drill it out the above may not work as the drill bit may have lodged the broken piece in the fastener worse.
I know these methods may sound crazy but I have seen it work. If it works it saves you from having to ruin your fastener.

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Thanks Gunny!

Your welcome. I know it may sound goofy but I've had it work for me. I had a very old aircraft mechanic ( my grandfather actually) show it to me on an high perf outboard I was working on.
Im just concerned it may have been already expanded from the drilling attempts….but it's an easy try. Try to use as small an orifice air nozzle with as much air pressure as you can. Again….wear some good leather gloves and eye/face protection as it can come out of there pretty fast….like a small projectile.

Is this a good gas block or a cheapo? If a cheapo just take a way oversize drill and drill out the set screw, threads and everything and get another block for $15. Or Dremel cutoff wheel and cut the block out from around the screw, or dremel a slot in the screw so you can get it loose with a flathead screwdriver and throw the whole mess away.

I always like the easy brute force method for stuff like this: angle grinder with a cutoff wheel. Then upgrade to an adjustable gas block.

Metabo

You would be surprised how many times I've been brought AR's with this very issue. Usually a bit from a generic multi bit kit. They are so small in diameter it doesn't tak much to brake them.

VERY rare I have to drill one.

I start with dental picks to see if I can pop the broken bit out. If that doesn't work but the bit will wiggle in the socket, I use CA glue (gel super glue should work too) to glue the broken bit tip to a new bit and pull it out.

I've never had to resort to this on a gas block but on other stuck bolts I can't get out by other means, tig welding something to the bolt itself usualy gets it done.

If I have to drill a tool, broken tap, etc I use a carbide bit. My preference in tools are: Foredom > Milling machine > drill press > handheld drill

Lh extractor bit, hand drill and vice fixed an identical problem for me.