Adjusting screwdrivers to fit the screws

[Bill2024]

I’m just wondering what normal practice is here. So far I have only worked on the st3620 movement but it seems to me that the width of many of the screws on this movement is much wider than the tip of the correct screwdriver. I have had quite a few slips because of this but not managed to break anything yet!

I’m comfortable sharpening and then blunting (not sure if that is the right term) the screwdriver tips but it seems I would really have to do a lot of blunting to get a correct fit on this movement. 

Is it common practice to regularly adjust screwdrivers in this way and would you to do this for each movement worked on?

I have a set of Horotec screwdrivers in most sizes for 0.6 to 3mm

Thanks, Bill

[tomh207]

My experience is you are constantly dressing screwdrivers to fit. The bigger the variety of movements the more you need to do it. If a watchmaker specialises in say, 2 or three movements they conceivably have a set of drivers dedicated to each.

 

Tom

[HectorLooi]

I have 3 sets of screwdrivers, fine, medium and coarse.

[Pip]

The professional watchmakers I know all have several sets of screwdrivers, each set honed for a particular movement or brand. I'm also often told not to use the same screwdrivers for quartz and mechanical, I guess because of magnetism, but I just de-mag mine often.

[Neverenoughwatches]

There is a few things I need to say here ....thats a shocker . So first off I'm assuming we are talking about the thickness of the tip that should WEDGE itself into the screw slot. Bottoming out of the tip in the slot is the common scenario of a blade about to slip out and indiscriminately scratch anything in its path. Particularly if the screwdriver is not held perpendicular to the screw head. Now I'm a joiner of 40 years and before that picked up my first driver at around 3 years old, apparently forcing it into the speaker of my dad's radio 55 years ago . So i should know how to handle a driver...yes ?   actually no i did not...not in the case of watchrepair. Mainly because the tips of watchmaker's screwdrivers are thin and have little surface contact. It took me a day on and off of scratching up old movements to figure out what I was doing wrong. The tip needs to fit the slot thickness snuggly as a wedge and not bottom out...that's it. Unless you are very good at holding your driver straight up and down. Reminds me of when my apprentices would hold a hand driver or battery driver at all manner of angles and wonder why they chewed up screw heads. " Hold the jeffing thing straight " I would whisper gently in their ear . Rambled on long enough me thinks... secondly learn to dress your drivers....nooo... not cute little outfits.....shape them. Nice accurate equal angled sides that fit as a wedge and a straight end. The wedge fitting sometimes lifts out the screw as well. I've seen folk polish driver tips ??? I dont get that, not completely , it might look nice and shiny and ward off some corrosion, but it has no grip. I generally go no higher than 400 grit, the flat bottom can be a bit rougher if you like. I like a bit of grip same applies to my soft tweezers, more so in fact. I dont repair Patek watches so I'm not fussed about zero damage to screw heads. If I did then i would change my ideas. And lastly the driver should more or less suit the size of your hands if they are one way or the other. I have stupidly large joiner's hands for a guy of only 5'9" , took me a while to get accustomed to using diddy tools. Oh and holding the driver head, more steady control is achieved by having it on the middle pad of your index finger and not on the last pad near you fingertip. Think thats it, I may be back later today....if you're lucky....or maybe unlucky as the case maybe

[Bill2024]

@Neverenoughwatches - thank you so much for taking the time to reply. I’m coming to realise that I may eventually need more screwdrivers but that’s a way down the road for now.

I’ll definitely have a go at fitting the drivers to the movement I am working on though, and be a bit braver in creating the wedge to prevent bottoming out in the screw slot as that’s definitely what happens at the moment. 

Interesting about holding the screwdrivers as well. I too thought everyone can use a screwdriver, but it turns out not so much when working on such a small scale. I’ll try using the different part of the index finger  

I have been using a 600 grit diamond plate (which I use for my hobbyist hand tool woodworking) to dress the screwdrivers but I may try something a bit coarser.