OT: 0.1mm flat screwdriver, any hint where to find it?

[Klaus Kragelund]

Hi

Sorry for the off-topic. I am doing a watch repair and need a 0.1mm flat
screwdriver. Been searching the web for 1 hour and got no hits

Anyone been down that road?

Thanks

Klaus

[TTman]

Try searching for jeweller's screwdriver ?

--
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[Klaus Kragelund]

On 28-11-2020 00:40, TTman wrote:
> On 27/11/2020 23:09, Klaus Kragelund wrote:
>> Hi
>>
>> Sorry for the off-topic. I am doing a watch repair and need a 0.1mm
>> flat screwdriver. Been searching the web for 1 hour and got no hits
>>
>> Anyone been down that road?
>>
>> Thanks
>>
>> Klaus
> Try searching for jeweller's screwdriver ?
>

I have. The smallest I have found is 0.5mm

[Klaus Kragelund]

I have one of these:

https://www.elfadistrelec.no/no/folerblad-rustfritt-stal-mm-bernstein-515/p/18075835

I think they are called sensor blade in english

I could cut the 0.1mm blade off, and try to use it as a screwdriver, but
that just seems plain stupid

[RheillyPhoull]

Would grinding a .5 work ?

[Jasen Betts]

On 2020-11-27, Klaus Kragelund <klau...@hotmail.com> wrote:
> Hi
>
> Sorry for the off-topic. I am doing a watch repair and need a 0.1mm flat
> screwdriver. Been searching the web for 1 hour and got no hits

that's a very narrow blade, maybe start with piece of 0.1mm spring
steel wire and rub it on a sharpening stone to form a blade,


--
Jasen.

[Jeff Liebermann]

Not me, but flat screwdrivers are easy to make. You'll probably need
to do that because a 0.1mm flat screwdriver is easily broken.

The smallest I could find is 0.5mm.
<https://www.esslinger.com/search.php?search_query=0.1mm%20flat%20screwdriver&section=product>

Start with whatever you have that looks like a jewelers screwdriver.
Use a Dremel tool and an abrasive disk or mini grinding wheel to
create the 0.1mm screwdriver tip. When making something that small
and pointed, you're going to ruin the existing heat treating no matter
how you do it and how you cool it. Heat the flat tip with a propane
or MAPP gas torch until it's cherry red hot. Dump the screwdriver in
oil or water as fast as possible. Test with a file. If a file skips
over the surface, you've hardened it. Then, anneal it down to a brown
or blue color. If you find that you can't harden it, it might be
"mystery steel". Use a spark test to check if it's high carbon.
<https://en.wikipedia.org/wiki/Spark_testing>

Something like this but with a much smaller screwdriver blade:
<https://www.instructables.com/Hardening-and-Tempering-a-Screw-Driver-softening/>

More details:
<https://www.google.com/search?q=hardening+screwdriver+tip>


--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[Jeff Liebermann]

On Fri, 27 Nov 2020 17:30:45 -0800, Jeff Liebermann <je...@cruzio.com>
wrote:

>Heat the flat tip with a propane
>or MAPP gas torch until it's cherry red hot. Dump the screwdriver in
>oil or water as fast as possible. Test with a file. If a file skips
>over the surface, you've hardened it. Then, anneal it down to a brown
>or blue color.

Steel tempering color chart:
<https://www.engineeringtoolbox.com/tempering-colors-steel-d_1530.html>

Tempering colors of steel:
<https://en.wikipedia.org/wiki/Tempering_(metallurgy)#/media/File:Tempering_standards_used_in_blacksmithing.JPG>

Any help in tempering jeweling screw drivers?
<https://mb.nawcc.org/threads/any-help-in-tempering-jeweling-screw-drivers.128120/>

[Jasen Betts]

flat blades are measured by width not thickness

--
Jasen.

[olaf]

Klaus Kragelund <klau...@hotmail.com> wrote:

>>> Sorry for the off-topic. I am doing a watch repair and need a 0.1mm
>>> flat screwdriver. Been searching the web for 1 hour and got no hits

>I have. The smallest I have found is 0.5mm

I have a 0.2x0.7. But I bought it in Tokyo at TokyoHands in Shinjuku.

https://shop.vessel-europe.com/de/product/251389

Perhaps buying one of this and sand it down?

But this shop offers one:

https://www.e-dohrmann.de/werkzeuge/uhrmacher-werkzeug/schraubendreher-05-bis-25-mm.html

...that is 0.5mm wide. So it is possible it is 0.1mm flat.

Olaf

[Mikko OH2HVJ]

There's a watchmakers and micromechanics school in my city and I've
bought some prototyping work as student work from there.

They learn to make their own tools before building watches - you've
found one of the reasons why they do this!
--
mikko

[Mike Coon]

In article <rps0ub$11ss$1...@gioia.aioe.org>, klau...@hotmail.com says...

How does anyone cut a thread on the screw that takes such a driver? And
who makes the die?

And so ad infinitum...

[TTman]

On 27/11/2020 23:09, Klaus Kragelund wrote:

That's about the width of a human hair. What screw is that small?

[Clive Arthur]

On 28/11/2020 00:00, Klaus Kragelund wrote:
> On 28-11-2020 00:09, Klaus Kragelund wrote:
>> Hi
>>
>> Sorry for the off-topic. I am doing a watch repair and need a 0.1mm
>> flat screwdriver. Been searching the web for 1 hour and got no hits
>>
>> Anyone been down that road?
>>
>> Thanks
>>
>> Klaus
>
> I have one of these:
>
> https://www.elfadistrelec.no/no/folerblad-rustfritt-stal-mm-bernstein-515/p/18075835
>
>
> I think they are called sensor blade in english
>

Feeler gauge.

> I could cut the 0.1mm blade off, and try to use it as a screwdriver, but
> that just seems plain stupid

--
C

[Klaus Kragelund]

Wow, it occurred to me, but I dismissed it, because how would you be
able to purchase the correct screwdriver then? :-)

But, thanks, that probably solves my issue, so I can go ahead and order
a 0.5mm one

[Klaus Kragelund]

Great explanation, thanks :-)

I have a blow torch, - and did metal hardening back in school 30 years
ago. So been a while. If I cannot find one that fits I will try your
idea out

Spark testing, I didn't know such a test existed. Fun stuff

[Klaus Kragelund]

Come to think of it, there is probably a standard for that, as there is
for the thread dimensions:

https://en.wikipedia.org/wiki/ISO_metric_screw_thread

[amdx]

Are we really talking about a screwdriver blade that is 0.004" wide?

Doesn't seem right.

                       Mikek

[Jeff Liebermann]

On Sat, 28 Nov 2020 08:55:48 -0000, Mike Coon
<gra...@mjcoon.plus.com> wrote:

>How does anyone cut a thread on the screw that takes such a driver? And
>who makes the die?

Small screw threads are rolled, not cut. Actually, just about all
commodity screws are rolled, not cut. Trying to cut threads into a
thin rod puts a radial stress on the bolt which will then break, bend
or deform the rod. Rolling does a better job of supporting the bolt
and work hardening the threads.

"Why are Rolled Threads Stronger?"
<https://www.youtube.com/watch?v=4YfQHJ4n6s8>

"The smallest screw in the world"
<https://www.youtube.com/watch?v=NerJ2yiT3xw>
<http://piepklein.blogspot.com/2012/01/begin-van-een-moertje.html>
<http://1.bp.blogspot.com/-xtsww5ydKIA/TvDsaQIJ2CI/AAAAAAAAATQ/zo-01jDGFa4/s1600/0135.jpg>
0.1mm dia. 0.25 um pitch (about 1000 tpi).

>And so ad infinitum...

Yep. Usenet discussions never end.

[amdx]

On 11/28/2020 11:45 AM, Jeff Liebermann wrote:
> On Sat, 28 Nov 2020 08:55:48 -0000, Mike Coon
> <gra...@mjcoon.plus.com> wrote:
>
>> How does anyone cut a thread on the screw that takes such a driver? And
>> who makes the die?
> Small screw threads are rolled, not cut. Actually, just about all
> commodity screws are rolled, not cut. Trying to cut threads into a
> thin rod puts a radial stress on the bolt which will then break, bend
> or deform the rod. Rolling does a better job of supporting the bolt
> and work hardening the threads.
>
> "Why are Rolled Threads Stronger?"
> <https://www.youtube.com/watch?v=4YfQHJ4n6s8>
>
> "The smallest screw in the world"
> <https://www.youtube.com/watch?v=NerJ2yiT3xw>

 This one touted as the smallest screw in the world, still has a head
that is 0.012" wide, so the 0.004" wide screwdriver is to small.

Now, are we talk about the tip thickness?

                       Mikek

> <http://piepklein.blogspot.com/2012/01/begin-van-een-moertje.html>
> <http://1.bp.blogspot.com/-xtsww5ydKIA/TvDsaQIJ2CI/AAAAAAAAATQ/zo-01jDGFa4/s1600/0135.jpg>
> 0.1mm dia. 0.25 um pitch (about 1000 tpi).
>
>> And so ad infinitum...
> Yep. Usenet discussions never end.
>
>


--

[Jeff Liebermann]

On Sat, 28 Nov 2020 12:10:32 -0600, amdx <am...@knology.net> wrote:

>> "The smallest screw in the world"
>> <https://www.youtube.com/watch?v=NerJ2yiT3xw>
>
>  This one touted as the smallest screw in the world, still has a head
>that is 0.012" wide, so the 0.004" wide screwdriver is to small.
>
>Now, are we talk about the tip thickness?

No. Flathead, slotted, or minus sign screw drivers are measured by
the width of the blade, not the thickness. Sometimes, you'll see a
2nd number after the blade width, which is the shaft length. Just to
make life difficult, some larger slotted screwdrivers include whether
the tip is flared (tapered), or parallel, which has more to do with
the diameter of the grinding wheel used to grind the tip than any
strength requirement. In general, 4mm or smaller slotted screwdriver
tips are nearly parallel.

In the distant past, I worked for my father in his lingerie factory in
Smog Angeles. During the 1960's, good screwdrivers were expensive. My
father favored Craftsman because he could exchange them when I fumbled
something and broke the tips. It was easy enough to regrind a slotted
screwdriver or even a Philips driver. However, the tip would not
last. If I wanted it to last, I had to heat treat (harden and anneal)
the tip. Nobody cared what they looked like, so all the tips were
always black from the used motor oil quenching[1]. Only the tips
(about 5mm) needed to be heat treated. Eventually, tool manufacturers
got the clue and started advertising drivers with blackened tips as a
premium driver, for a premium price, of course. The problem was that
few of them actually bothered to harden the tips. Proto Tools
hardened them:
<https://www.google.com/search?q=proto+screwdrivers+black+tips&tbm=isch>
but the other manufacturers simply plated or painted the tips black.
For example:
<https://i.imgur.com/zXgVIZ3.jpg>
The same thing happened later when interchangeable tips became
popular. The good tool manufacturers heat treated the entire driver,
while the junk was just black paint:
<https://www.youtube.com/watch?v=0_pB2R9KNzg>
<https://www.youtube.com/watch?v=Y7RSfVqbjSo>

Some basics in heat treating hand tools:
"How To Heat Treat / Temper Hand Tools & More!"
<https://www.youtube.com/watch?v=I9lgwNp7v0E>
There's far more if you want to get into cryogenic heat treatment,
which is what the high end knife makers use.

For a tiny 0.1mm, the heat treating is critical. Too soft, and the
screwdriver will twist in the slot. Too hard, it will break. Properly
hardened, it will have the strength, without also being brittle.


[1] Quenching should be in used, not new oil, so that it is full of
carbon which provides a form of surface case hardening.

[amdx]

 I didn't get my point across. You posted what was supposed to be the
smallest screw in the world.

It had a a head the was 0.3mm across. Why would you need a screwdriver
that is 0.1mm wide for that screw.

I think that would be a bad choice, It seems to me a screw driver 0.3mm,
or 0.25mm  wide would be better.

Does Klaus have a screw that is smaller than the worlds smallest screw?
OK being a little factitious there.

Klaus, how wide is the slot on the end of the screw you are working on?

                                             Mikek

[Klaus Kragelund]

I just took some pictures

Watch disassembled:

www.electronicsdesign.dk/tmp/watch/1.jpg

Screw and 0.2mm sensor blade

www.electronicsdesign.dk/tmp/watch/2.jpg


It's a little to wide to fit in the flat slot, so I figured I needed
0.1mm screwdriver

Picture of sensor blade:

www.electronicsdesign.dk/tmp/watch/3.jpg

It's a citizen divers watch

[Jeff Liebermann]

On Sat, 28 Nov 2020 23:36:19 +0100, Klaus Kragelund
<klau...@hotmail.com> wrote:

>www.electronicsdesign.dk/tmp/watch/1.jpg
>
>Screw and 0.2mm sensor blade
>www.electronicsdesign.dk/tmp/watch/2.jpg
>
>It's a little to wide to fit in the flat slot, so I figured I needed
>0.1mm screwdriver
>
>Picture of sensor blade:
>www.electronicsdesign.dk/tmp/watch/3.jpg
>It's a citizen divers watch

Sensor blade = feeler gauge in the US.

Oh-oh. The 0.1mm seems to be the width of the slot in the screw head,
also known as the thickness of the screwdriver blade. This slot width
is normally not specified. You don't need a 0.1mm wide screwdriver.

Googling a little, it looks like one of the Citizen divers watches is
43 mm diameter:
<https://twobrokewatchsnobs.com/citizen-eco-drive-promaster-diver-review/>
Using the photo #1
<www.electronicsdesign.dk/tmp/watch/1.jpg>
to scale the watch diameter against the screw head diameter:

33mm screw_head * 43mm watch_diam / 720mm watch_diam
= 1.97mm screw_head
(The 33mm and 720mm are as measured on my computah monitor)

A 2mm screw head diameter is a much more reasonable screwdriver size
for watch screw than 0.1mm.

[speff]

Here is a Swiss datasheet that shows the tip dimensions for various sizes:

https://www.bergeon.swiss/synchronisations/pdf/8018%20A%20B%20C.pdf

Screen capture in PNG: https://i.imgur.com/B9o9zOG.png

At $300 for a set of 10 with a rotating base, not inexpensive, but the tips are replaceable.
Tempting if you like nice tools, the tips are going to be properly formed and heat
treated to be hard yet not too brittle.

Best regards,
Spehro Pefhany

[amdx]

On 11/28/2020 4:36 PM, Klaus Kragelund wrote:
>
>>>
>>   I didn't get my point across. You posted what was supposed to be
>> the smallest screw in the world.
>>
>> It had a a head the was 0.3mm across. Why would you need a
>> screwdriver that is 0.1mm wide for that screw.
>>
>> I think that would be a bad choice, It seems to me a screw driver
>> 0.3mm, or 0.25mm  wide would be better.
>>
>> Does Klaus have a screw that is smaller than the worlds smallest
>> screw? OK being a little factitious there.
>>
>> Klaus, how wide is the slot on the end of the screw you are working on?
>>
>
> I just took some pictures
>
> Watch disassembled:
>
> www.electronicsdesign.dk/tmp/watch/1.jpg
>
> Screw and 0.2mm sensor blade
>
> www.electronicsdesign.dk/tmp/watch/2.jpg
>
>
> It's a little to wide to fit in the flat slot, so I figured I needed
> 0.1mm screwdriver
>
> Picture of sensor blade:
>
> www.electronicsdesign.dk/tmp/watch/3.jpg
>
> It's a citizen divers watch

 Near as I can figure it, the the distance across the screw head is
0.8mm and I'll agree with Liebermann about the slot width being 0.1mm.

https://www.dropbox.com/s/ddxeyrnfy84iniu/watch%20screw.jpg?dl=0

This is huge, at 2.66 times larger than the worlds smallest screw. :-)
To small for my eyes, and I'm not real shaky, but

at the end of a 2" screwdriver, I'm sure it would take a few tries to
hit the slot.

I pulled the smallest screwdriver from my Dollar Store kit and it
measures 1mm and the tip thickness is .3mm. That won't work.

This 9pc kit goes down to a 0.5mm blade. $17.69

> https://www.amazon.com/Loriver-Precision-Screwdriver-Slotted-Watchmakers/dp/B087LRD5TC/ref=sr_1_16?dchild=1&keywords=watchmaker+screwdrivers&qid=1606655549&sr=8-16

[Klaus Kragelund]

Yes, that might work. I will go ahead and buy it. Thanks