We have an old Ikea office chair that was in need of a wash. The seat was removed and then the back was removed. The back had a bracket on it which clamps to the seat. To allow for proper washing of the fabric, I removed the bracket and took the cloth off the back so that it could be washed.
Later when I came to put the cloth back onto the frame, I noticed that the frame for the back should have four bolt holes, but one was blocked. I tried poking it out, expecting that it was some debris, but it turned out that the bolt had broken off in the hole while being removed.
I tried using a screw remover in my hand drill, but it couldn’t get any purchase on the hardened bolt – so I had to think of something else. I could try drilling it out on my mill, but I would have to work out how to clamp the frame in the vice. I found a piece of wood that I drilled two holes into, then used other bolts to mount it on the frame.
I was able to clamp the wood in the vice. This allows me to get at the broken bolt – from the inside aspect so that if I try drilling it out with a 4mm drill bit, it may screw out of the hole, out the bottom. After a bit of force, it was drilling away then suddenly gave way, as the broken part of the bolt screwed out of the bottom of the hole. This technique works only if you have a through hole, not a blind hole.
Here you can see where the drill was cutting into the piece of bolt, when it threaded out. It is shown next to the bolt that had broken off. Fortunately, there was still enough thread on the bolt to securely fasten the bracket back onto the frame for the back.
Now, you might ask – what if the drill just drilled straight through and I still have part of the bolt inside the hole? I still have a few choices. I could continue to drill progressively larger holes until I reach the minor diameter of the bolt. This will leave a sliver of metal in the shape of a spiral or a spring, which could then be picked at and unwound out of the hole.
Another method would be to use either of these screw removers.
This one will go into a hand drill and used in counter-clockwise rotation. It is used if a screw or bolt is stuck in a hole, and is used from the outside of the hole. It will drill a tapered hole which eventually will jam and unscrew the broken bolt.
This type is one which will jam into an existing hole – like the one that I had been drilling. I would use the size that is smaller than the hole, in counter-clockwise direction, it will eventually jam in the hole and unscrew the bolt or screw.
Of course, definitely wear eye protection in the form of safety glasses – it isn’t unusual for the drill to suddenly break and a piece goes flying, or metal slivers coming off the bolt could be dangerous to your eyes. Anyway, another successful Remove.IT – of a broken bolt.
Oh, what if the bolt is broken in a blind hole? A similar technique can be used, is to get a left-hand drill bit to do the drilling, except that using this in a mill or drill press will not unscrew the broken bolt since the mill/drill is putting downwards pressure on it. Once the hole is drilled, then using the screw extractor in a hand-held drill in reverse will usually do the trick. If it doesn’t, then we have to continue to drill larger diameters with left-hand drill bits and then pick out the remaining sliver.
If that doesn’t work, then it is possible to just drill it out and use a helicoil or thread insert. This is used when the threaded hole is damaged – such as if it had been cross-threaded or damaged by using the wrong threaded bolt. We won’t get into that now. Thanks for reading.
R.IT 