[Cynthia Moore]

I have a very old (20 years?) Aeron chair. The arm rests are wobbly and they do not fit under my desk. So I thought I'd remove them. I did a little research and came across this video:

https://tinyurl.com/ycaztqo6

Following his instructions, I was able to remove the back of the chair. The four hex bolts were super tight. They required a lot or pressure to loosen them, but once I did, they came right out.

The bolts inside that hold the arm rests on are torx. I found the right size wrench, but am unable to loosen them. In the video, he says they are torx and seems able to loosen them fairly easily.

Mine do turn slightly, but whichever way I turn them, they seem to get tighter.

Back to the Internet, I found this method:

https://tinyurl.com/ya3lw5sq

If this guy is correct, H-M locked these nuts in place with some kind of glue. A-holes.

Should I try to apply as much pressure as I can and hope for the best?

Should I try heating the bolt as suggested? And why use a series of ever larger drill bits? Why not start with a larger one?

What about drilling out the head of the bolt?

I don't care if I ruin the arm rest as they were broken anyway. I just don't want to damage the rest of the chair.

 

[hkstroud]

The bolts inside that hold the arm rests on are torx. I found the right size wrench, but am unable to loosen them. In the video, he says they are torx and seems able to loosen them fairly easily.

Put the Torx bit in a 1/4" socket. Put the socket with the bit on a 1/4" ratchet extension, put that on a 1/4" ratchet. That will give you the leverage to over come tension of the bolt and the resistance of the thread locker adhesive.


Note that in the second internet reference you made it was noted that the left arm used a left hand thread.


Remember: Righty/tighty, lefty/loosey.

Meaning turn to the right or clockwise to tighten. Turn to the left or counter clockwise to loosen.



A left handed thread means that the threads are the reverse. So you turn counter clockwise to tighten and clockwise to loosen.

Should I try heating the bolt as suggested? And why use a series of ever larger drill bits? Why not start with a larger one?

I would not suggest using heat at this time. You don't know what you will burn and you do not need to to heat the thread locker material if you set up the Torx head bit as described above.
By using a small drill bit that will almost, but not quite, fit inside the Torx recess you enlarge the recess. Then using a slightly larger bit you enlarge it more. You do this until you have drilled away the entire head of the faster. Doing it this way your drill bits stay centered on the bolt head. Starting with the largest bit you don't know where the bit will go, most likely off to one side. Leaving you with part of the bolt head which you cannot remove.

 

[Cynthia Moore]

Put the Torx bit in a 1/4" socket. Put the socket with the bit on a 1/4" ratchet extension, put that on a 1/4" ratchet. That will give you the leverage to over come tension of the bolt and the resistance of the thread locker adhesive.

My torx wrench is part of a folding set, not a separate tool, so I can't do that unless I go buy a separate wrench, which I can do if necessary. But I am able to apply quite a bit of force using the handle of the set.

I was able to loosen the one on the right arm, but after a few turns, it seems to turn without making any progress. That was the arm that has been wobbly for a couple of years. I wonder if that bolt is broken.

Note that in the second internet reference you made it was noted that the left arm used a left hand thread.

Yep. The one on the left that I did manage to loosen turned in the usual way. I tried the one on left both ways, but I wasn't sure if really was left-handed, so I didn't apply as much force as I could have. I try it again with max force in the morning when I have better light.

Remember: Righty/tighty, lefty/loosey.

That's not a political statement, is it? ;-)

I would not suggest using heat at this time. You don't know what you will burn and you do not need to to heat the thread locker material if you set up the Torx head bit as described above.

OK

By using a drill bit that will almost but not quite fit inside the Torx recess you enlarge the recess. Then using a slightly larger bit you enlarge it more. You do this until you have drilled away the entire head of the faster. Doing it this way your drill bits stay centered on the bolt head. Starting with the largest bit you don't know where the bit will go, most likely off to one side. Leaving you with part of the bolt head which you cannot remove.

OK

Thanks very much for the detailed explanations, Harold.

 

[hkstroud]

That's not a political statement, is it? ;-)

No, it just a way to remember which way to turn nuts and bolts.


Of course politicians naturally know how to screw things up.

1/4" or 3/8" ratchet and socket set would probably be of great convince to you. Increase your physical strength.

Archimedes Quotes
"Give me a lever long enough and a fulcrum on which to place it, and I shall move the world."

 

[Cynthia Moore]

By using a small drill bit that will almost, but not quite, fit inside the Torx recess you enlarge the recess. Then using a slightly larger bit you enlarge it more. You do this until you have drilled away the entire head of the faster. Doing it this way your drill bits stay centered on the bolt head. Starting with the largest bit you don't know where the bit will go, most likely off to one side. Leaving you with part of the bolt head which you cannot remove.

The guy in that writeup talked about "cobalt drill bits". I have a set of "Heavy Duty" drill bits from Ace Hardware. Are they tough enough?

If not, what should I get? I see both cobalt and titanium bits.

 

[Cynthia Moore]

Being the patient, careful, methodical person that I am, I went ahead and gave my heavy duty drill bits a try. They seem to be working pretty well.

I started with a 5/32 bit and gradually increased. I just finished with a 9/32 bit. There is a pretty big hole now in the head of the bolt where the torx slot used to be.

What am I looking for? At some point, will the bolt head come completely off?

 

[Cynthia Moore]

I just finished using my 3/8 bit, which is the largest one I have.

The bolt for the left armrest appears to be drilled all the way through, but it still seems securely attached.

The bolt for the right armrest seems much harder. It's more of a brass color.

I have attached the best photos I could get.

Any suggestions on where to go from here? Do I need to go buy a larger bit? Should it be cobalt or titanium?

 

[hkstroud]

The term "Heavy duty " is meaningless. Cobalt and titanium are metal additives which are added to regular steel to make the bits a little harder and more resistant to wear.

Don't know what the bolts or screws of the chair are made of. They will be made of a metal a little harder than the regular screws and bolts you would find in the bins at Home Depot or Lowe's but not that much harder. Try you regular metal bits. You are not going to be doing that much drilling. You only need to drill away the head of the bolt. When the head is remove the arm will come off the bolt. The remainder of the bolt will stay in what ever it is screwed into.
Just stick your drill bit and you should be able to tell when it has centered itself in the the recess of the Torx head. The bit should effectively enlarge that recess. The next size up bit should enlarge that hole more. You keep doing that until there is no head on the bolt. You won't be drilling very deep, probably no more that 1/4".
Drill slowly. We all (me included) want to drill at high speed. But speed increases heat and that is what dulls metal drill bits.

 

[hkstroud]

Just saw your photo. You simply need larger bits. Those are probably stainless steel bolts.

 

[Cynthia Moore]

Just saw your photo. You simply need larger bits. Those are probably stainless steel bolts.

OK, I guess I'll go over to Home Depot -- if they are even open.

How much bigger do I need to go? 1/2"? 3/4"?

Do I need to get the cobalt or titanium bits? If so, which?

 

[hkstroud]

Do I need to get the cobalt or titanium bits?

Six of one half a dozen of the other.
If 3/8 was last bit you used you will need a 1/2" at least. Hard to judge size from photos. You may also need a 5/8.

1/2" easy to find, in every small metal drill bit set. 5/8 would probably have to be purchased separately.
Don't know what kind of drill you are using. Most small drill won't accept any drill bit larger that 1/2". If you find a 5/8 make sure it has a reduced shank so it will fit into your drill.

 

[Cynthia Moore]

Six of one half a dozen of the other.

Ok, I'll see what they have in stock.

If 3/8 was last bit you used you will need a 1/2" at least. Hard to judge size from photos. You may also need a 5/8.

1/2" easy to find, in every small metal drill bit set. 5/8 would probably have to be purchased separately.

OK

Don't know what kind of drill you are using. Most small drill won't accept any drill bit larger that 1/2". If you find a 5/8 make sure it has a reduced shank so it will fit into your drill.

OK, no laughing now. I've attached a photo of the drill. It's a very old Craftsman. I think I bought it around 1970 or so.

 

[hkstroud]

I probably have a couple of those around also. Can't tell from photo but yours is probably a 3/8. Meaning it will only take bits up to 3/8". So get bits with reduced shanks.

 

[Cynthia Moore]

I probably have a couple of those around also. Can't tell from photo but yours is probably a 3/8. Meaning it will only take bits up to 3/8". So get bits with reduced shanks.

I got a 1/2" cobalt bit with a reduced shank. I put it to the bolt on the left arm rest and after about 5 sec of drilling, the head popped off. Great!

The bolt of the right is a whole other matter. It's not the same metal at all. I've been working on it for 10-15 minutes and I can't tell if I'm making any progress at all.

I'm going to giver it a rest and try again later.

 

[Cynthia Moore]

Success! (Finally)

I spent another 10-15 minutes trying to drill out that right bolt head making very little progress. I also tried going back to the smaller bits trying to widen the hole to give the 1/2" bit less to work with.

Looking at the head, it seemed like it was almost through. So I got a chisel and a hammer and drove the chisel in between the head and the chair from the side. After a couple of tried, I was able to bend one side of the head up. Using a pair of 90° needle nose pliers, I was able to rip one side off. Pushing down on the arm rest, I was able to pop it off.

Do now I have my new chair.

Thanks, Harold, for all your help.

 

[hkstroud]

Congratulations. Some things just take perseverance. Nothing succeeds like success. If I could I would take you out to dinner.