What is the name of the tool used for this bushing?

Crappy picture, yes. 

This is a brass bushing that screws onto another tube, and it requires a tool that grips like a two-pronged adjustable width fork in the two cuts that are 180 degrees opposite one another, on either side of the shaft hole.  I have mangled a few of these in a hurry, using the blades of wire cutters.  I don't think I've ever seen this tool, but I've never looked before either. 

Snap ring pliers can do it sometimes, or needlenose, but really, like with some microphones, this requires a watchmakers wrench, used to open the backs of watches.  I forget what it is called by start with googling watchmakers wrench watch case wrench etc. and move from there.

http://www.esslinger.com/screw-on-watch-case-opening-wrench-square-pins.aspx

http://www.aliexpress.com/item/Repair-Screw-Remover-Watchmaker-Tool-GJBP0019-Adjustable-Watch-Back-Case-Wrench-Opener/795763834.html

I can't tell how big it is from the picture but there are screwdrivers like this http://www.shop.pbtools.us/PB-196-Screwdrivers-for-Round-Nuts_c68.htm

DIY time!

For small slotted rings like that I have sacrificed old or cheap screwdrivers and filed a slot in the middle.

For the bigger ones I take a strip of brass and again cut or file a slot so that you get a blade at each end. You can also use a piece of metal pipe of the right size and file that to make a nifty tool!

Thanks guys, good ideas there.  The 'screwdrivers for round nuts' looks most like what I imagined.  Actually something between that and the watchmakers wrench that is adjustable is what I imagined. 

The shaft hole is 1/4", overall diameter is about 1/2".  I should get a tool before a tear up any more of these. 

Gold said:

I can't tell how big it is from the picture but there are screwdrivers like this http://www.shop.pbtools.us/PB-196-Screwdrivers-for-Round-Nuts_c68.htm

Click to expand...

Oh... those are cool.  What size does a 1/4" and 6.3"" collet knob do you know.  I had to make my own.

There are MANY styles of the watchmakers tool.  The key differences in them are the shape of the points (which should be hardened steel) and the depth of the point (I modified mine to open Oktava mic pads because my points were too thick) and how close they can come together (This can be the hardest thing to figure out, and your fastener seems small.  It is not a common fastener and thus not very easy to figure out exactly what you need, but many of the wrenches are cheap.

There is also a type of "ring spanner" shaped approximately like a crescent moon with a fish hook barb, which could work.  For your size the screwdrivers look best.

bb

emrr said:

Thanks guys, good ideas there.  The 'screwdrivers for round nuts' looks most like what I imagined.  Actually something between that and the watchmakers wrench that is adjustable is what I imagined. 

The shaft hole is 1/4", overall diameter is about 1/2".  I should get a tool before a tear up any more of these.

Click to expand...

YES!  Collet knobs, I never think about those.  Same thing. 

Someone told me they'd used a hose clamp to wrap around parts like these, then pliers to get it all to move.  Sounds like an emergency move. 

That PDF is huge, here's the relevant screen capture from page 88.  Mine would be the largest of those options, if it's even big enough. 

emrr said:

Crappy picture, yes. 

This is a brass bushing that screws onto another tube, and it requires a tool that grips like a two-pronged adjustable width fork in the two cuts that are 180 degrees opposite one another, on either side of the shaft hole.  I have mangled a few of these in a hurry, using the blades of wire cutters.  I don't think I've ever seen this tool, but I've never looked before either.

Click to expand...

perhaps http://www.mcmaster.com/#drilled-spanner-drivers/=mxma5d

JR

I think the difference between the swiss tool and the mcmasters tool below is that the swiss one works on NUTS (I think it has a hole in the center of the shaft to accomodate the bolt). The mcmasters one works on screws but I think if theere was a nut (or a shaft coming through a collet) it would not allow you to get in there.  I am not sure of that, but that's how I read the catalog.  I ordered the swiss one, I can tell you for sure in a week or two. 

update:
(Just received it, doesn't work for Sifam collet's, which is why I bought it, the blade is too thick.

You can see a round nut that the PB Swiss Tool was designed for.

Those are like what I'm dealing with. 

If you are ordering from them do yourself a favor and order a flat head screwdriver. They have a unique head shape that doesn't mar the screw head. They are the best flat head screwdrivers I have ever come across.

I usually make my own tool out of a big flat steel washer.  I cut whatever slot I need with the abrasive cutting wheels in a Dremel.

hi, maybe these ("jack nut driver" or "plug jack driver")?  :

http://www.antiqueradios.com/forums/viewtopic.php?t=161012

http://tabiwallah.com/radiowallah/shops/jacknut.html

http://www.engineer.jp/en/products/dj01_07e.html