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Screws broken off in screw plate.

Ticktinker

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I just received a screw plate from an Ebay seller.
2 Screws are broken off flush in the plate. I have tried soaking in PB Blaster penetrant for 6 hours.
I have been trying to pick at them and trying to encourage them to twist out with a needle in my pin vise.
One is in the 10 spot and the other in the 15 hole. The ten is large enough for me to have begun trying to file a driver slot in it with my screw head files. These pieces are very hard. should I try something like naval jelly or Sulfuric acid (drain cleaner) to make the parts release?
I have some tiny broaches... how should I get the smaller one out?
Any help will be appreciated.

Dave.
 

Skutt50

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Sorry I can not help you. I have a plate with the same problem.

The only thing I know is that what is left is not coming loose easy. They often broke when someone tried to cut threads in a too big rod, meaning they are very stuck! Not like a broken screw in a movement which often is more or less loose as is.

I really hope someone comes up with a solution.
 

karlmansson

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I think the plates are carbon steel so acid would affect the plates in the same way as the screw but even worse as the exposed surface area is so much bigger.

Try mounting the screw plate in a face plate if you have access to one and maybe drill it out with a stout spade drill. In some cases I hear it's also possible to turn the headstock by hand and catch the screw with the tip of the graver and turn it out that way.

Best of luck!
 

gmorse

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Hi Dave,

This is a tough one! The trouble is that you're dealing with steel on steel, and when screws are turned so tight that they break, the effect is almost like welding. Acid will attack the plate as well, so that's out. I think Karl's idea is a good one, if you can mount the plate in a faceplate and centre it properly to catch a centre and drill out the broken piece.

Regards,

Graham
 

Ticktinker

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Does anyone know of a chart for the Martin #42 screw plate that shows the raw diameter recommended for each screw size on the plate?
 

Ticktinker

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I think, when I have to make some screws, I will be taking out my drills and seeing which one fits onto the bevel landing on the numbered side.
That will make a decent guage to mic to determine my blank size.

- - - Updated - - -

Does anyone out there have an army of fleas equipped with tiny tools:???:
 

ScottS778

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I have used an electric engraving tool to get some stuck screws out in the past. I have been known to modify the point of engraver for small screws. get an adjustable force engraver and go at it. If the screw plate is what I am thinking of it may look like a modern threading die, it will have clearance slots for the chips to curl out. If you not able to form the point of the engraver to get hold of the end of the screw and hammer it out you may be able to grind the point into a chisel shape that will fit down in the chip clearance relief and shave the screw out of the screw plate.

Just throwing out wild ideas. I got the engraver idea from a locksmith, there were some screws broken off in an aluminium door, the engraver works like a tiny jack hammer to help you ease the screw out.

Scott
 

Ticktinker

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Scoot I see a lot to take to consideration in your post...
There are commercially made vibratory removal tools out there for larger bolts.
It did not come to mind until you said it...
The screw plate I have has chip holes on both sides of the threaders.
I have considered just taking a broach and filing across the screw with one small enough not to cut the plate, and just work on it as if it were my nervous tick...
Carry it around with me and file and fiddle with it all the time :p
 

Smudgy

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Try cutting it into parts with a jewelers saw. The saw kerf should give enough free spade to allow the screw to release.
 

dAz57

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yes that is how I cleared a couple of holes on my plates, you might go through a few saw blades but it worked for me
 

topspy

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ScrewExtractor.jpg I have this thing, which fortunately I have never had to use. It is designed to remove broken screws from watch plates where you have access to both ends of the screw. You tighten the runners on both ends of the screw and rotate the watch plate to remove the screw. Perhaps you could cobble something together using a C clamp or such?
 

laprof

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This has worked for me (as goofy as it may sound). Put a drop of RSC Liquid Wrench (available at auto supply houses or Wal Mart) on top of each broken screw. Let it set for about 30 minutes then put the plate in your freezer for a couple of hours. Freezing causes metal to shrink, but different metals shrink at different rates and that is the key. Then put your plate immediately into your oven that has been preheated to 450 F. The heat will now cause the plate to expand back to its normal size and the screw will too, but at a much slower rate (don't ask me why, I'm not a metallurgical engineer). Take the plate out of the oven and immediately try to remove the broken screw with a fine pick (I used a very fine graver). It should turn freely, just don't burn yourself. Oh, to anticipate an objection, no, it won't hurt your jewels or warp your plate.
 
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Ticktinker

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Top spy,
Super idea!
I have some small pieces of plate, just about thick enough to drill screw holes in.
Turn down some screw ends to make the pin points needed...
 

Ticktinker

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LA Prof,
Sounds feasible, I considered something like that, and did not know if it would work...
I think I will give it a shot.
Thanks.
 

karlmansson

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Top spy,
Super idea!
I have some small pieces of plate, just about thick enough to drill screw holes in.
Turn down some screw ends to make the pin points needed...
If I'm not mistaken, the screws need to have serrated tips to be able to grip the metal of the broken off screw. Never owned one of these but they have come up in discussion Before and the general opinion struck me as sceptic.

I like the idea of the heat expansion thing! One concern would be annealing the plate though... Just to add to your possibilities, apart from the liquid wrench solution a penetrating oil recipie came up on this board a whila ago. Equal parts acetone and transmission fluid. Emulsified finely Before use.
 

LarFure

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Use a very fine punch and drive it out. The broken screw is softer than the screw plate, and driving out the screw won't hurt the threads in the plate.
 

RJSoftware

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I have an old Morse die that is for larger size, but thing about it is it's a split die having two halves. The outer shape of this die I am talking about is square and fits in a square die holder. You twist the handle and it closes the die halves together.

A couple things come to mind on this. First is that if this where some triangular arrangement with 3 closing die blades, then one could adjust the die for any size stock. To me this is an interesting prospect. One die does all diameters for a specific tpi (threads per inch).

But then this makes me wonder what tpi is used on most screw plates. Or am I mistaken and there is some kind of graduating standard which increases tpi as diameter decreases?

The screw plate does have a tendency to break the stock especially the smaller we get and the lathe holding the stock firm and the hand jerks slightly and snap..! I need a chart on my bench for expected stock sizes. Especially for stem making.

But thinking about the split die brings me to another possible solution and that is to make split dies from a screw plate. But the holes are so small. Maybe one could cut the plate just on the side close to the screw threading hole and then grind closer. Then put a flat bar that simply helps to push the stock into the threading die half. Or maybe cut only 1/3rd or so off. Leaving a negotiable opening for a stuck screw to be pushed out the side.

RJ
 

Ticktinker

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RJ,
I am not getting what you mean about a morse die...
On the matter of increasing number of threads from size to size, I would say yes, because of the need for mechanical advantage that is created by a low enough pitch in thread to resist loosening... Otherwise you have a fastener akin to a machine Identification plate pin which has steep pitch grooves, that is tapped into place with a hammer. The more threads per measure, the better the holding capability,,,
Dave.
 

RJSoftware

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Ok. If the die where composed of two halves held together by holder, then if the stock broke off inside you simply take the thing apart and remove the broken piece.

The other point I was making is that if two halves where held with an adjustable distance then they could thread a variety of stock sizes.

If there where 3 sections and they could be held at adjustable distance then you have same thing but could conform to any diameter curve. Think 3 pointed tips that could come to Zero size or above. Like a Jacobs chuck acts.

But they would all create the same threads per inch.

So all that is needed dies with different tpi's.

And they would never suffer from stock being permanently stuck inside because you could open up the diameter.

RJ
 

karlmansson

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Many modern dies have the possibility of compressing them slightly, allowing for an altered fit between the created screw and recieving thread. Have a look in "Watchmaking" by George Daniels, he does adress it.

I see what you are looking to accomplish RJ but there are several problems with it. The first is just as you say yourself, you will get the same pitch of thread for each diameter. Have a look at the M-system threads. The pitch increases proportionally to the diameter. By using a system such as the one you are describing you will have created custom threads that noone will be able to work with in the future. You would have to make a tap to suit your given pitch and diameter from how your die is set up.
Second is the question of how such a die would be manufactured and how the halves would be held steadily enough to be able cut with stability and reliability. And lastly: when you change the diameter you will also change the cutting angle of the Points of Contact with die and stock.

I can't tell you what pitch the die plates are normally but it does not correspond to the M-system. I've thought about cutting a screw for a while and measuring it manually.

Best
Karl
 

RJSoftware

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Hey Karl.

Like a dang mystery trying to find the set "norm" for the taps and dies.

I understand what you said about the pitch increasing with decreasing diameter. But we almost understand each other.

What I am saying is you have a set of dies that can adapt to a range of diameters and the dies are different tpi (different pitches).

So you have a set of dies much like Jacobs chucks but allow pass through. They can be adjusted 0 to whatever.

Your first die has 15 tip it may have a range of 0 to 1/2 inch.
2nd has 20 tpi and so on...
30
40
50
60 etc...

Or whatever pitches that are required. I assume you to mean that as tpi increases so does pitch (being angle in threading)...?

The only trick then would be to make sure the stock is the correct diameter that is normally required of a normal die to thread it.

I picture the die acting much like a 3 jaw chuck where the stock is inserted to the destination end and then die blades are drawn inward like a 3 jaw chuck in even proportions until they grip the stock.

Starting at the normally end of the thread allows the die to be adjusted to whatever the diameter is. The cutting goes backwards by turning opposite (unscrewing). It may require a couple of passes to get the thread correct depth.

RJ
 

RJSoftware

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Another option on the screw removal from screw plates is to cut slots all the way to outer edge. Preferably on both sides. Then one could twist the screw plate a degree, that might help in removing the piece, then twist back so the tool is still usable. Just enough angle to make the cutting blades spread a bit and then twist it back. Probably would want to maintain the center portion of the screw plate with no slit. Bending often might crack the plate too.
 

RJSoftware

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Hey Graham, how do you remove them when they break off small?
 

karlmansson

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My take home message from this thread is that you don't.

Regarding your hypothetical die RJ: yes, TPI is a measurement of thread pitch. It's just that we don't do threads per inch here in Europe.
You're would still be dealing with a cutting relief that would be inappropriate as you changed the diameter though, if you were to make your three jaw chuck thing.
 

gmorse

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Hi RJ,

Karl is right, once they're broken off in there, that's where they stay. The only possible way I can think of is to drill them out, and for that you need to follow Jerry Kieffer's methods and equipment if you want to avoid damaging the plate.

Regards,

Graham
 

RJSoftware

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There is a split plate version (2 sides that separate, sizes 20 to 6 I think) for sale online but the guy wants a bit more than I am willing. I like the idea of it though. If I screw up (forgive pun) then I don't have to worry.
 

RJSoftware

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To all who have followed this thread and future here is one solution I have found.

On the screws stuck in regular threading plate a carbide Dremel drill bit can be sharpened to point with diamond wheel. Spinning drill bit in lathe and grinding tip to fine point with diamond wheel on Dremel tool.

After establishing a needle fine tip then two flats can be ground on sides to form a basic spade-like tip with needle like point. Then that tip is used to drill on backside of broken screw stock to force broken screw stock to reverse out.

The carbide is what makes it happen as it eventually eats the grip that the stock has stuck into the cutting teeth of the die.

Here is a tap/die set that uses same principles I was trying to express above. But this one is simple as a screw tightens up the gap and forms the die into the established desired results (with properly sized stock).

When the screw is released the die expands back and if it where that the stock was broken the extra gap should make it much easier to remove.

So it is like a split die and yet not. :)

The taps I do not like as the same sized die serves as grip to hold the tap. But the dies are good design.

RJ
wiru1.jpg

wiru2.jpg
 

karlmansson

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Hey! I have one of those sets! Not with the taps though. Do you know the name of the maker? I got mine second hand with no info. Any word on if they are metric? What type thread they correspond to?

Karl
 

RJSoftware

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Hey Karl. All I really know so far is that they are WIRU from Germany. That they are metric. Mine has a label and perhaps you could elaborate. I have translated the German text and it talks about being for watchmakers but don't really understand the table.

Here is pic. Mine is E2 as previous owner underlined E2.

wiru4.jpg

Hey! I have one of those sets! Not with the taps though. Do you know the name of the maker? I got mine second hand with no info. Any word on if they are metric? What type thread they correspond to?

Karl
 

karlmansson

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The holder in my set actually says WIRU now that I look at it. I think the case for mine is shop made so it's probably not much help. It has a note stuck in it similar to yours though. I tried to run a case screw into a die that said 08 and it went in smoothly! Great to know that I've actually got some good dies that are metric!
 

RJSoftware

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Least you got a hippo. Mine is a weasel floating on a rotten log. Least I hope he is floating on a log. It's brown anyway, :(


Yes somewhat. The one you have in link is much more interesting and I like the automatic open/stopping.

They have the kind I was thinking about on ebay but it is made for ear-ring jewelry making (If I recall correctly). Anyway, the whole point is the dies adjust to the diameter of whatever is being threaded.

The whole concern for all of this was just avoid screws breaking off in plate and being too hard to remove.

The WIRU set I have works fine but is not standard of US watchmaker size. The #9 (I have yet to determine) is the most popular size of stem extenders. But sometimes stem extenders fail to do the needed thing in easy stem repair. So I wind up cutting a new winding stem and dang things do tend to bust/break when threading.

Free hand turning a lengthy diameter has mixed results. If it gets too tight then "tink" you know that dreaded sound.

RJ
 
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