Unusuall size die & tap

Hi

I'm looking for an unusual size die. It's "about" M2x0.35mm. I say "about" because, measuring the diameter of the screws I need to replace, the largest diameter ones are actually 2.02mm. One source claims this is a M2.1x0.35mm thread, which is possible since these screws (for musical instruments) are often on the smaller end of the diameter range.

Any idea where to get an unusual die like this, and preferably a tap too?
Alternatively, any suggestions how to make them? This is too small to single cut on a lathe (I assume?). I've only ever made taps or dies this small by using a tap and die (to make a die and tap respectively).

The largest standard 0.35mm die is M1.8. I have an adjustable one but this seems too much to enlarge it.
Another option I thought of is to enlarge an adjustable 1-72 die. The thread is short enough that this would work well, and the diameter (before enlarging) is supposedly 1.85mm. I'm not sure if I've enlarged an adjustable die in that size by that much before. Is this worth trying?

Thanks

What is worse case if 1-72 does not work? Maybe try it on a piece of annealed steel, if it works you have start of your chaser tap, if it does not work you are out a die and a tiny piece of steel. seems risk/reward favors going for it. No one did anything cool without a little improvisation.

have you had a good look at Floyd Automatics ? …….that sort of thing is right up their street Threading Dies | Floyd Automatic Tooling

Is this a clarinet pivot screw?
Allied Supply lists 2.1x0.35m for a Schreiber clarinet
or 2.0x0.35m for a Buffet Contra Alto Clarinet.

Allied doesn't list anything that uses a 2-72
But, musical instruments (as you know) use a lot of odd-ball threads.
Just wondering whether this thread is of metric origin or imperial origin.

Victor Machinery Exchange does list a 2-72 in a round adjustable die.
Could that be adjusted enough to cut the thread tight enough to fit your situation?

High Speed Steel Round Adjustable Dies, Special Thread to 1/2"

Good luck,
Jess

It really sounds like some over-eager metric idiot metrifucated a 2-72 thread. I suspect you can just get and use that readily available tap and die size. In theory the tap will be just a bit bigger then 2.1mm so it will be OK. An adjustable die should take care of any English-metric problems there. And the difference in pitch is less than 1% so no one will ever notice and few would be able to measure. I certainly would not want to try that measurement on a screw that is only about 1/8" (3mm) long.

As for cutting this on a lathe, a good lathe with a dead sharp tool should be able to do it. After all, taps and dies do not come out of molds at the steel smelter. Someone had to cut them in the first place and that probably meant a lathe.

Note: Don't ask me about the source of "metrifucated", just use your imagination. I just do not understand the need to redefine things that have been established for decades in English units. Any metric conversion that will be compatible will be a odd metric size and CONFUSING. If it is defined in inches, just leave it that way, for Pete's sake. And if you are going to change to metric, then USE A REAL METRIC SIZE.

Thanks.

Worst case is my 1-72 die breaks... and since good quality HSS adjustable dies are not available here, it means an international order, which means very high shipping cost for a tiny part or waiting until I need to make a larger order from a place that has it. Hardly the end of the world but thought I'd ask about enlarging it by that much before trying it.

OD of a 2-72 seems to be 2.18mm. So reducing by about the same amount as enlarging a 1-72. Reducing is probably a lot "safer" (as far as breaking) but I think also harder...?

Yes this is for a clarinet and these screws are old and not available anywhere anymore. I asked Allied specifically and other suppliers, no one seems to stock them (I stock many different ones for many brands and models as it's usually cheaper/faster than making them).

Re metric/inch, it's from a company that uses only metric now... They used to supply a tap for this size, which I assume was made for them by a local company. As Jess mentioned instruments used to have all sorts of weird thread sizes.

I'll get a 2-72 and try both that and the 1-72 to check. Making a tap from a die is much easier for me than making a die from a tap. It's adjustable and and I use the tap on softer materials (die generally to thread tool steel, tap generally to thread cupronickel).

If a readily available screw could be made to work (by going up a size and running the appropriate tap through the holes), is is worth converting all the pivot screws to the new size?
With the new screws, and the appropriate tap, it would go fairly quickly.
This would save the grief every time you (or someone else) work on the instrument. It might be a little more expensive now, but be better for the long-term health of the instrument?

Isn't working on old stuff fun?????

-Jess

clarnibass said:

Thanks.

Worst case is my 1-72 die breaks... and since good quality HSS adjustable dies are not available here, it means an international order, which means very high shipping cost for a tiny part or waiting until I need to make a larger order from a place that has it.

Click to expand...

IMO Not necessarily so - from the UK anyway, go here Get a price | Royal Mail Group Ltd

FWIW I got say a die in a ''large letter'' starting at under £3.00 sterling.

jwhartley said:

If a readily available screw could be made to work (by going up a size and running the appropriate tap through the holes), is is worth converting all the pivot screws to the new size?

Click to expand...

I can explain the many reason why not if interested

Limy Sami said:

FWIW I got say a die in a ''large letter'' starting at under £3.00 sterling.

Click to expand...

Do you know of a source for good quality HSS split dies in the UK? I guess I'll still have to check whether they'll ship that way (most places don't IME).

I gave you one in post #3 - Floyd Automatics, ………..I'd be surprised if they didn't ship to Israel

Drill Service (Horley) Ltd are another reliable quality only pro tooling outfit, Dies and Dienuts

Update 1 - I've just spoken to Drill Service and was told they would do Israel and it would be best for you to register on their website.

Update 2 - I've spoken to Floyd Automatics and they will also ship to Israel.