Remove tiny broken bolt

[Nor'Easter]

Some vibrations tonight led me to snap an insert off a 2" shell mill, well the insert is fine it's the tiny bolt that holds them on that broke. It's about 2mm major diameter and broken off maybe 20-25thou below the plane that the insert sits against.

Any ideas?? Am I going to be on the hunt for a micro left hand bit?

Looks sort of like this. The head is a T5.

 

[Monkey Milk]

Are those though holes, go from the back with a regular RH bit to unscrew.

 

[cgrutt]

I just ordered a small left bit to replace one I broke in my extractor set. That would probably be where I would start.

McMaster's has 135 degree left bits to 1/16 and 118 degree bits to 1/32.

http://www.mcmaster.com/#standard-drill-bits/=11ux8q7

How small is the screw?



Good luck.

 

[cadavjo]

Are those though holes, go from the back with a regular RH bit to unscrew.

What he said

 

[maxpower_hd]

What about one of those screw extractor deals? I got some as a gift but haven't had the need to try them yet. It has sort of a drill on one end and the extractor on the other. If the screws aren't very tight it should work. Worst case you can probably drill the head of the screw clean off and remove the insert then use small pliers or Vise Grips for the remainder of the screw? Not sure if I'm reading the photo right. But I recently did that on some exhaust manifold bolts that were busted off. Removed the remaining ones and Vise Gripped the broken ones right out once the manifold was removed.

 

[rlitman]

I doubt it is "stuck" under the surface. Just broken.
I'd use a tiny pin and matching tiny hammer to try to turn it out.

 

[APEowner]

The good news is that the remaining part probably isn't tight all. I'd start with a magnifier some deep breaths and a dental pick. If that doesn't do it and they are indeed thru holes then a drill in from the backside will most likely turn it out. If it's blind then I'd try a drill blank ground to a flat blade type tip spun backwards.

 

[Kevin54]

Is the insert still on the cutter or did it come off when the bolt broke? Like mentioned, I'd go at it from the back side with a standard drill. But if everything is still under pressure, then you are going to have a hell of a time getting it off. The easiest way is to get the head off of the screw if possible to get the insert off, then you should be able to get the screw out relatively easy. I've broken a few off, and I take the head of the screw off to remove the insert. Use the same size bit as the hole in the insert. The carbide will act like a drill bushing. Just make sure you leave some of the screw sticking up to be able to grasp and turn it out.

 

[Jim Johnstone]

Edit, didn't read the entire post, I thought the screw head stripped out with the insert still on.

 

[kkroger]

I'd first try to use a ***** punch to get a purchase on the broken stub and see if I could apply sufficient pressure to back it out. If you have never removed a broken screw this way then you may not understand I would bet Kevin has and maybe a couple others. that tiny little screw cannot be in there that tight...

 

[Nor'Easter]

Thanks guys. Hadn't thought of going at it from the back. Yes the hole runs through.

 

[DougWil]

If you think it is loose, try vibrating it out with gravity and something that vibrates.
I will leave the latter to your ingenuity.

 

[Guster]

I had this happen with a lathe tool. Small drill was wandering too much to get good purchase without damaging the threads. Used a carbide scribe to make enough of a slot in the face of the stub to back it out with a small screwdriver. The screws tend to be fairly soft.

 

[Jim Johnstone]

I was able to get a busted screw out of face mill once by using a pencil grinder from the back side and it eventually grabbed and spun the screw out.