I have an office chair where the locking mechanism needs tightening. I think the right way to do it is turning this nut, but the problem is that the space is so tight that if I get an adjustable or open-end wrench in I can't turn it. Is there some kind of specialist tool for this kind of job? I think some kind of very thin open-end wrench with a ratchet on the open end could be what I need, but they seem expensive and hard to find.
EDIT: As you can see in the image, it is a very tight fit with an open-ended wrench and there are some metal rods the wrench hits that limits the range of motion even more.
Best Answer
I would propose that you go to a pawn shop or thrift store and get an open end wrench.
You could then grind away as much of the sides or the shoulders as you can but still leave enough so that it is structurally sound. ( will not bend )
If you do not have a bench grinder then clamp it to a work bench and use an angle grinder.
OR, try a universal style wrench,
This kind fits over the nuts and allows you to tighten it in one direction and then rotate it back without having to take it off of the nut. You may need to grind it as well.