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I spent the day literally watching paint dry. I was using black lacquer to fill in the engraving on a pocket watch case to make it stand out. I will send pictures when it is finished. In the mean

This should put your mind at rest. Click on this link. http://members.iinet.net.au/~fotoplot/sdriver/sdriver.html  

Like others on here I don't restrict myself to just one set of screw drivers. I have one set ground to a thinner profile, and another set ground to a slightly fatter profile. I also have numerous scre

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On 10/12/2016 at 12:23 PM, TimFitz said:

I spent the day literally watching paint dry. I was using black lacquer to fill in the engraving on a pocket watch case to make it stand out. I will send pictures when it is finished.

In the mean time I was looking for screwdriver sharpening stone holders on the net. The sticker shock was amazing.

So i said to myself, "Self" your only watching paint dry, make your own, you have a sharpening stone and some wood. So I made this from scrap wood while watching paint dry. I'm happy with it & it cost nothing. It is perhaps not as pretty as Bergeon but they have enough money. 20161012_110004 (Small).jpg

Nice sharpener.  Apparently, watching paint dry can be a productive use of our time.

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Please don’t get fixated on hollow grinding. With our small gauge screwdrivers, to achieve a concave grind of correct geometry would require wheels of a few mm in diameter. A readily available small diameter dremmel wheel would effectively have a ‘flat’ circumference on the tiny contact area being sharpened. So, hollow grinding is in theory ideal, but not practical. I use a fine oilstone and 3 in 1. With practice I am achieving good driver contact and no screw damage.


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  • 4 months later...

Gunsmiths have run into this problem a lot because external screws are decorative.  In order to protect the top edge of the screw's groove you don't want a tapered screwdriver or a hollow ground screwdriver you want a parallel ground screwdriver.  At the size you guys are working with this may be a moot point as Deggsie has said but it's valuable to know what you are going after.  Tapered and even hollow ground screw drivers can engage the top or leading edge of the notch which is it's weakest point, this is what causes deformation of the screw notch.  Ideally you want to engage the whole slot, or the base of the slot, not the top edge.

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On ‎1‎/‎18‎/‎2018 at 6:40 AM, vinn3 said:

"carless jewelers' ?  I say - amateur  mechanics !  it happens in cameras also.  so, get your money back  and

 

learn how to sharpen a screw driver. vin

   it is quite sad to see a valuable watch, camera or clock.    with "upset screw heads"

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1 hour ago, milotrain said:

Gunsmiths have run into this problem a lot because external screws are decorative.  In order to protect the top edge of the screw's groove you don't want a tapered screwdriver or a hollow ground screwdriver you want a parallel ground screwdriver.  At the size you guys are working with this may be a moot point as Deggsie has said but it's valuable to know what you are going after.  Tapered and even hollow ground screw drivers can engage the top or leading edge of the notch which is it's weakest point, this is what causes deformation of the screw notch.  Ideally you want to engage the whole slot, or the base of the slot, not the top edge.

   what ever it takes to get near 100%  contact in the screw head,  including the top edge.   another good subject is "restoring" screw heads.    vin

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you can also harden the tips. after heating them on your kitchen stove till they glow a bit, dip them in motor oil. this will increase the carbon content of the steel , hardening the surface. they seem to last a little longer between sharpenings.

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On 6/19/2018 at 2:17 AM, vinn3 said:

    another good subject is "restoring" screw heads.    vin

I would be interested in that.

'Chewed' screwheads irritate me, I'm not set up yet to restore screws in watches, but its on my list of things to get set up to do.

Feel free to start a topic on restoring screw heads, I certainly would be interested.

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1 hour ago, yankeedog said:

you can also harden the tips. after heating them on your kitchen stove till they glow a bit, dip them in motor oil. this will increase the carbon content of the steel , hardening the surface. they seem to last a little longer between sharpenings.

I am going to try this.

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6 hours ago, Tmuir said:

I would be interested in that.

'Chewed' screwheads irritate me, I'm not set up yet to restore screws in watches, but its on my list of things to get set up to do.

Feel free to start a topic on restoring screw heads, I certainly would be interested.

   there is an excelent post on bluing screw heads someware on this forum.   the bad thing about it is buying a watch with pre "chewed" heads and having to say "I dint do it" !  vin

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On 2/5/2018 at 2:07 PM, mhorlogerie said:

The best way to adjust drivers is with an abrasive stone. You can use a holder but it is also possibly to do it by hand. I prefer a Norton India stone, I have tried diamond stones and those work as well. 

Norton stone ?  The very best.

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7 hours ago, oldhippy said:

Sometime ago I went through how I would tidy up and blue screw heads for clocks. If you want that, I can go through that again. Just ask.

I know how to blue screws, but I am interested in how you get screws back to a state ready to be blued

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1 hour ago, Tmuir said:

I know how to blue screws, but I am interested in how you get screws back to a state ready to be blued

  well,  put them in a lathe,  resurface them,  put them in a mill and enlarge the slot.   best buy new ones.  vin

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Cleaning screws and blueing.

I cleaned clock screws up using a lathe, but you can also use a screw head polisher. Take the rough edges or burr off by using your needle files or small bench file. Then use various emery sticks finishing with the finest to produce a very fine finish. You then need to burnish the complete screw head. You then need to clean the screws; I used an old watch cleaning machine with old cleaner and rinse.

I used to blue the screws using an old copper penny in a hand vice which was over a spirt lamp (you don’t want a long wick) the hand held was then held in a bench vice. The trick is to blue all the screws to the same colour blue. If you fail, then clean the blue off and start again. As soon as the screw has turned to the required blue quench the screw in oil, this makes the screw shine. Clean the screws again in the cleaning machine, dry and cool. If you are successful, all the screws will be an even colour blue. It takes a little practise.

There are a few ways of bluing screws. My master taught this way me.    

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On 6/18/2018 at 12:16 PM, milotrain said:

Gunsmiths have run into this problem a lot because external screws are decorative.  In order to protect the top edge of the screw's groove you don't want a tapered screwdriver or a hollow ground screwdriver you want a parallel ground screwdriver.  At the size you guys are working with this may be a moot point as Deggsie has said but it's valuable to know what you are going after.  Tapered and even hollow ground screw drivers can engage the top or leading edge of the notch which is it's weakest point, this is what causes deformation of the screw notch.  Ideally you want to engage the whole slot, or the base of the slot, not the top edge.

100% agree....but in the common vernacular, hollow ground is used to describe the resulting parallel, and desired, end you describe- i.e. the curve is a hollow vs the flat side of a regular screw driver.  Its what Wheeler and Brownels call them (this the set I have, and recommend it)  https://www.btibrands.com/product/professional-gunsmithing-screwdriver-set-89-pc/

I've do a lot of work on old machines and lathes (Schaublin 70's, Holbrook B8, rivett 608 etc) and a lot of these are put together with slotted head fasteners; some predate socket head cap screws.  Its really a shame to some of the nicest machines man's ever made scarred because some hack took a screw driver to them.  The trick is one  of those large gunsmith screw driver kits with hollow ground blades of different widths and thicknesses.  For stubborn ones you can put a wrench on the bit and it loosens without damaging the screw heat

Having said all that, I haven't weighed in on watch screws as (from lack of experience with watches specifically) I'm not sure of the necessity as it may be that the torque/contact ratios are different such its not required, and secondly the world best makers of watchmakers tools don't bother (although Bergeon does offer hollow grinding rig irrc) nor do many watchmakers who I view as highly competent.   I've a lot of books on watchmaking and cant' recall reading it (at least that I remember).  You'd think if it was important, given screwdrivers are the most used tool in this craft, tied maybe with tweezers, that if it was oh so important, hollow grinding them would be the first chapter in every book, yet it seems rarely or never mentioned.

bit of a zombie post.....didn't realize how old that one was :)

 

 

 

 

 

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Hollow ground screwdrivers are really only of use if you work on the same model of watch all the time.

The reason is if your flat ground screwdriver is too thin you just stone a tiny bit off the end to make it fatter.

On a hollow ground screwdriver you need to remove a lot more material to make it fatter, and then hollow grind it again to suit the screw you want to undo, so its harder to swap between brands of watches that you need to adjust your screwdrivers for.

If you worked as an 'in house' watch repairer of an expensive brand of watches, and always did the same movements then hollow ground is the best, but for most of us that works on what ever watch comes our way the flat ground is best being a compromise between time taken to reshape screwedrivers and the risk to 'chewing' screws.

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  • 8 months later...

Dear All,

 

My nice Bergeon screwdriver set was chipped after few watch services, was looking for a sharpening kit to repair them, but I soon realized I own a Lansky knife sharpening kit, so I pop the screwdriver blade out and give it a try, the results are very promising, see the photos, it's easy to use and versatile, comes with different stones, if I like, I can even use the ceramic stone to give it a high polish, and I can always use it to sharpen my folding knives, what do you think? Love to hear them.

 

Darak

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