What's the technique to anneal thin carbon steel consistently ?

[mikepilk]

Do you buy or make your pivot drills ?

[Neverenoughwatches]

9 minutes ago, mikepilk said:

Do you buy or make your pivot drills ?

They are bought but i would like to have a go at making some.

[mikepilk]

Cousins don't seem to sell them, but I see HS Walsh do. 

They look more robust than a normal HSS drill. Any HSS drill <1mm has a very short life expectancy with me.

[Neverenoughwatches]

24 minutes ago, mikepilk said:

Cousins don't seem to sell them, but I see HS Walsh do. 

They look more robust than a normal HSS drill. Any HSS drill <1mm has a very short life expectancy with me.

I think thats just a factor of how hard and thin they are. Under 1mm care is needed its a thin drill. Tthey have to be hard enough to drill steel parts but not so hard that they break easily. Those carbide drills from ebay 10 for £5, i though they were ok when i got them but drilling this piece even in its annealed state i broke 4 of them within a few seconds, absolute rubbish but @HectorLooi said that. 

[Neverenoughwatches]

20 hours ago, mikepilk said:

To anneal steel, heat it up about 100 degrees F above its critical temperature, soak it at that temp for 1 hour per inch of thickness, and let it cool at a maximum rate of 70 F per hour"

So, for the thicknesses we are working with, say <0.5mm, the time held above critical temperature would only need to be 1-2 minutes.  The problem is knowing how hot your metal is in the centre of the charcoal, and how long the cooling process needs to be.

For thin small parts that might be difficult, they lose heat rapidly in air, within minutes. Normalization temperatures can be in excess of 1000°C for that we are looking at cooling periods of over half a day. A good cheap solution might be a vented cylinder placed in an open fire or woodburner, i wish i still had mine

[HectorLooi]

My mentor taught me a method which I haven't used yet. That is to embed the metal in a small piece of soft charcoal, like those artist use for drawing, and set it alight. The embers will continue to burn for awhile and the carbon dioxide produced from the combustion would prevent fire scale from forming.

[nevenbekriev]

19 hours ago, Neverenoughwatches said:

I think thats just a factor of how hard and thin they are. Under 1mm care is needed its a thin drill. Tthey have to be hard enough to drill steel parts but not so hard that they break easily. Those carbide drills from ebay 10 for £5, i though they were ok when i got them but drilling this piece even in its annealed state i broke 4 of them within a few seconds, absolute rubbish but @HectorLooi said that. 

Guys, this is stange that You search for the hardest way to do the job. The drills mentioned abowe drrill hardened steel with no need of anealing, like piece of cake.  I will make video to show how.  I see one mistake here of making the lever: The first thing to do is to plase the broken lever on the material and drill the holes thru it as a conductor. Then - to put tapered pins in the holes that will hold the old lever on the material, to drow the contures with sharp tool, and only then - to start cutting

[Neverenoughwatches]

1 hour ago, nevenbekriev said:

Guys, this is stange that You search for the hardest way to do the job. The drills mentioned abowe drrill hardened steel with no need of anealing, like piece of cake.  I will make video to show how.  I see one mistake here of making the lever: The first thing to do is to plase the broken lever on the material and drill the holes thru it as a conductor. Then - to put tapered pins in the holes that will hold the old lever on the material, to drow the contures with sharp tool, and only then - to start cutting

Hi thanks nev, this was my first attempt at making a part. The process you have just described is  how i said i would do it next time.

https://www.watchrepairtalk.com/topic/27897-my-first-watch-part/?do=findComment&comment=234382

1 hour ago, nevenbekriev said:

The drills mentioned abowe drrill hardened steel with no need of anealing, like piece of cake

Which drills do you use Nev ? Must be different to the ones i tried. Carbide drills yes but the ones i used were a cheap version bought from ebay, extremely poor quality. The only others i have are old pivot drills that would not drill through the steel of feeler gauges that i used for the part. These tungsten carbide one are absolute trash, very brittle.  I'm sure there are much better quality ones.

Edited December 3, 2023 by Neverenoughwatches

[mikepilk]

1 hour ago, nevenbekriev said:

Guys, this is stange that You search for the hardest way to do the job. The drills mentioned abowe drrill hardened steel with no need of anealing, like piece of cake.  

Really? I'm missing something. Please show us how. 

Unless you have something like a diamond coated drills, the material is as hard as the drill?

All the drills I've tried won't touch the steel unless annealed, and my files just skate over it. 

Edited December 3, 2023 by mikepilk

[nevenbekriev]

1 hour ago, Neverenoughwatches said:

Hi thanks nev, this was my first attempt at making a part. The process you have just described is  how i said i would do it next time.

https://www.watchrepairtalk.com/topic/27897-my-first-watch-part/?do=findComment&comment=234382

Which drills do you use Nev ? Must be different to the ones i tried. Carbide drills yes but the ones i used were a cheap version bought from ebay, extremely poor quality. The only others i have are old pivot drills that would not drill through the steel of feeler gauges that i used for the part. These tungsten carbide one are absolute trash, very brittle.  I'm sure there are much better quality ones.

Yes, exactly this cheap drill bits. I use them for everything - repivotihg, drilling steel, making tools out of them. Yes, they are brittle, but this is the life - can't have something that hard that is not brittle. Simply have to learn how to use them without breaking them

[Neverenoughwatches]

28 minutes ago, nevenbekriev said:

can't have something that hard that is not brittle. Simply have to learn how to use them without breaking them

I understand that Nev, but the ones i used the cutting edge chipped instantly. Unless I have been unlucky with a batch of them but @HectorLooi said he had the same experience with them. I would love to know what you did differently .

[nevenbekriev]

First to learn is how much force one can use safely. The second - how to sharpen the bits. It is easy to try, to break or chip the bit and then to decide that they are good for nothing. No, it is not bad batch, for sure. Just practice needed. But, usually they are not good enough sharpened, may be recicled/resharpened after use in manufacturing PCBs. But that's OK, as they have to be sharpened often, until getting to short and then used for something else.

[Neverenoughwatches]

36 minutes ago, nevenbekriev said:

First to learn is how much force one can use safely

Ok thanks Nev i was thinking this might be the problem. I am using them in a pinvice on a static piece of work where pressure is not easy to control. They may perform much better under the speed of a power drill or against a revolving piece of work in a lathe. Many of us here dont have access to either a lathe or a powered micro drill.

A fluted drill bit should work better than a simple pivot drill.  

I understand what you mean though, i use hss drill bit sizes down to 2mm at work and there is a definite technique of barely touching the workpiece for a couple of seconds and then backing off.

3 hours ago, mikepilk said:

Really? I'm missing something. Please show us how. 

Unless you have something like a diamond coated drills, the material is as hard as the drill?

All the drills I've tried won't touch the steel unless annealed, and my files just skate over it. 

I am of the same opinion tbh Mike, Nev is either doing something different, technique would be a factor, or the quality of the drills is different. As regards to files, i did make a triangle profile one from a 2000 grit diamond plate, the type used for sharpening tools. 

Edited December 3, 2023 by Neverenoughwatches

[nevenbekriev]

I also use pinvice, one that has cap like screwdriver. OK, I will make a video and will make holes on not anealed watch spring, filler gauge... When making holes on the lathe, I prefer to hold the drill bit and press it to the work with fingers, and no big speed is needed. I use special tool that leads the bit to the work center. I have shown this repivoting techic here, the same kind of  drill bit 0.25mm used in the video.

 

[mikepilk]

The bottom line is, you can only drill hardened steel with a harder steel. If it's too hard for my file to cut, then what is your drill made out of that will cut it?  And even if it can, it's no good as I cannot shape it with jewellers saw and files. I need to anneal it anyway to shape it.

[Neverenoughwatches]

35 minutes ago, mikepilk said:

The bottom line is, you can only drill hardened steel with a harder steel. If it's too hard for my file to cut, then what is your drill made out of that will cut it?  And even if it can, it's no good as I cannot shape it with jewellers saw and files. I need to anneal it anyway to shape it.

A jewellers saw is definitely not going to cut hardened steel it has to shaped with a grinding stone or a diamond wheel,and finished with a diamond file and fine profile stones. A steel cut file will shape it but not for long it soon rips up the teeth. The annealing attempt i made makes filing and drilling easier. The cooling time needs to be slowed down further, inserting the cylinder into a heatproof insulated box. Next time i fire up my chiminea i will chuck a few feeler gauges and some scrap carbon steel in middle of it.

Edited December 4, 2023 by Neverenoughwatches

[Neverenoughwatches]

22 hours ago, HectorLooi said:

My mentor taught me a method which I haven't used yet. That is to embed the metal in a small piece of soft charcoal, like those artist use for drawing, and set it alight. The embers will continue to burn for awhile and the carbon dioxide produced from the combustion would prevent fire scale from forming.

Still might cool too quickly Hector, from what i did the cooling needs to be slower than one hour. 

[nevenbekriev]

OK, I made some videos to show that drilling hardened still is normal thing, when tungsten carbide drill bits are used. Actually, this is the same as turning hardened steel on the lathe - this is normal practice in watchmaking.

On the video with clock spring - this is 0.35mm thick spring, as hard as a spring can be. There are two interrupts in the video - that was for sharpening the bit. On the second one, which was at the end of drilling, the tip of the bit chipped. This happens, and for avoiding it, something must be put under the piece, with close hardness, and the piece should be pressed to it.

The video with the old rusty filler gauge shows that it is much easier to cut. The gauge is 0.3mm. This gauges usually are made of spring steel, which is something totally different from normal carbon tool steel, and annealing it usually can't bring it as soft as carbon steel.

See, heat treatment of steel is another, not simpe skill, craft... Annealing always leads to burning carbon int the steel and not only, then hardening and annealing can easy ruin the still and make it really crunchy if overheated. It usually takes many hours of practice to learn how to heat treat, and every different kind of steel has it's own ways and rules. So, this is much much easier to use readily heat treated steel and shape it in this state. Shaping is easy with carbon dental separators on the dremel tool, then fine with diamond files.

 

Edited December 6, 2023 by nevenbekriev

[Neverenoughwatches]

Hey all, been a while since the last post but i have some update info on drilling hardened steel for setting levers, @mikepilk if you're interested . It's a real shit of a job without the right gear After annealing my setting lever i did manage to drill 2 holes the first was ok and relatively quick i think i was just lucky and had something right,the second was tough and the other 2 i needed i just gave up. Pivot drills work but not great, this is supposedly after annealing. The steel is softer and shaping files seem to cut better, but hand drilling with the cheap carbide drills just does not work they break and chip like billyoh, unless...............you have the right gear. This is someway of getting the right gear. Proxon micro drill, the runout 1 1/2 from the head i cant see with x20 loupe holding a .4mm carbide bit. Proxon drill press stand makes it very useable. It isn't cheap but it is , its kind of entry level micro drilling and milling but on a fair quality tool. 0.4mm cheap crappy carbide drills eat through hard and tempered setting levers and feeler gauges ( nothing annealed ) at 5000 revs, the lowest the micromot 240v can go. No chipping of the carbide, but there is a technique involved, you cant just push your way through in one go and i think that might be to do with hardening of the steel as the drill end sits burnishing away on the surface of the steel or maybe the bit needs to bite in. The bit has to bite and back off a dozen times to get through but its about 30 seconds to 1 minute depending how brave you are, i drilled dry so a drop of oil could very well improve the situation. Its not the exact setup i was after but i figure i have some multi use here . Proxon do a few bigger more versatile milling machines and Dell put me onto a make that I'm considering but more like next year now. The little setup i have here is a little introduction to milling for me, i think i like it for now.

Edited February 29 by Neverenoughwatches

[mikepilk]

Using carbon steel from a feeler gauge, I must have got lucky the first time I annealed. The hole drilled just like it was mild steel - it just went straight through. Shaping with a file was also so easy.

The next time I used the same set of feeler gauges. Annealed as before ... and broke 2 drills. Couldn't touch it. Took three more attempts at annealing before I could drill a hole. But it still wasn't as soft as the first time.

I now have a steel cannister (an old box spanner with the end hammered over) and some activated charcoal for my next attempt at annealing.

[Neverenoughwatches]

14 minutes ago, mikepilk said:

now have a steel cannister (an old box spanner with the end hammered over) and some activated charcoal for my next attempt at annealing.

I tried that and i thought i had made a decent job of it.  The cooling down period was probably not long enough. It drilled but not that easily. These cheap carbides are ok and they do drill hard steel but they need to run fast and straight, there is no manual hand drilling with them. And still there is the slower process of shaping the piece if its still hard but it is doable by hand . I'm hoping this little mill will template hard steel.