# Truth and Myth About DLC, Duratech and High Tech Diamond and Scratch Resistance



## herbolaryo

The most durable (hard) material that can be used is Diamond.
Other materials like ceramics, sapphire crystal, stainless steel and titanium are softer compared to materials...

That is according to an objective measure of hardness which is the Vicker's scale... As shown on the Rado website....
















http://www.rado.com/usercontrols/po...onimages/rado/materials/haertescala_small.jpg

Here are some clarifications:

1. Is the Vicker's scale the same measure of scratch resistance?:think:

2. Since Diamond is the hardest... Is Diamond-Like Carbon (DLC) the same as High Tech Carbon?:think:

3. Is DLC the same as Duratech?:think:

4. What are other names of DLC or High Tech Carbon? (It seems like the word Duratech is only found in Citizen watch... It might be called by different names depending on the brand of watch):think:

5. Is it true that although titanium is light, it is SOFTER than stainless steel?:think:

6. I understand that their are methods/processes like plating, combining with other metal, etc. that makes a material more hard or scratch proof. What are these methods and how do you rank them from hardest to softest?:think:

7. At this moment, which watch/watches can you consider the most "scratch-resistant" of them all (scratch resistant in all the case & bracelet)?:think:


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## Piezo.Quartz

1. Yes, it's one scale of measure for hardness. Read more on this wiki.

2. It's diamond-like. The purest form have the carbon atoms arranged in a tetrahedron, but are amorphous instead of crystalline like in diamond. I don't know about the high-tech carbon referenced though.

3. No. Duratect (that's the correct spelling) is a Citizen trademark. It's (I believe) Japlish for "Durable Technology" or "Dura-tech-ko" and encompasses multiple forms of surface protection technology. DLC is used in some forms of Duratect.

4. Seiko calls their version Diashield. Casio, UTS and Ball stick with DLC, as do Citizen when they employ it.

5. Yes, pure Ti has lower surface hardness. However, on a per weight basis, Ti has superior strength.

6. Generally, precious metal plating improve only looks. In fact, these watches probably scratch more than modern SS. As for the rest, in general, CVD (a common one is IP) is better than PVD. However, it does depend on type and thickness. The best is to harden the surface via kolsterizing before coating/plating followed by DLC.

7. The Casio MRG-7xxx and 8xxx are some of the very best today, as are Citizen's Attesa ATV53-2834 and similar. I'd rate the Casio's DLC process to be slightly better than Citizen's.


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## herbolaryo

Piezo.Quartz said:


> 1. Yes, it's one scale of measure for hardness. Read more on this wiki.
> 
> 2. It's diamond-like. The purest form have the carbon atoms arranged in a tetrahedron, but are amorphous instead of crystalline like in diamond. I don't know about the high-tech carbon referenced though.
> 
> 3. No. Duratect (that's the correct spelling) is a Citizen trademark. It's (I believe) Japlish for "Durable Technology" or "Dura-tech-ko" and encompasses multiple forms of surface protection technology. DLC is used in some forms of Duratect.
> 
> 4. Seiko calls their version Diashield. Casio, UTS and Ball stick with DLC, as do Citizen when they employ it.
> 
> 5. Yes, pure Ti has lower surface hardness. However, on a per weight basis, Ti has superior strength.
> 
> 6. Generally, precious metal plating improve only looks. In fact, these watches probably scratch more than modern SS. As for the rest, in general, CVD (a common one is IP) is better than PVD. However, it does depend on type and thickness. The best is to harden the surface via kolsterizing before coating/plating followed by DLC.
> 
> 7. The Casio MRG-7xxx and 8xxx are some of the very best today, as are Citizen's Attesa ATV53-2834 and similar. I'd rate the Casio's DLC process to be slightly better than Citizen's.


Thanks for the input Piezo.Quartz.

Can you tell more about the CVD, IP, PVD, kolsterizing....?


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## Piezo.Quartz

Google and wikipedia are your best friends. There are also a couple of excellent posts on this forum you'll be able to find with key words like "scratch resistance" "kolsterizing" "ion plating" etc.


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## herbolaryo

I saw some post in
http://forums.watchreport.com/index.php?showtopic=239

It was discussed that&#8230;
The 2831 is pure Duratect.
The 2832/33 is Duratect with partial DLC.
The 2834 is Duratect with full DLC.

I saw in Citizen website that there is a Citizen Attesa ATV53-2933.
http://citizen.jp/attesa/lineup/rcw/532933.html

So it is questionable whether the new Citizen Attesa ATV53-2933 have only PARTIAL DLC coating...

Indeed... the coating process has many variables...
It can be partial or complete... 
So advertisements on watch can be a bit tricky... 
If they say Duratect + DLC--- be sure to ask if it is partial or complete...

I wonder what improvements will there be in a Citizen Attesa ATV53-2934


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## John MS

The problem I see with any of the applied finishes has nothing to to with their relative hardness. It has to do with what happens when the finish is inevitably scratched or chipped down to the secondary surface. My understanding is that the damage is not repairable and cannot be polished out as with stainless steel. Additionally, the surface and subsurface materials may contrast and highlight an otherwise minor scratch.


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## herbolaryo

John MS said:


> The problem I see with any of the applied finishes has nothing to to with their relative hardness. It has to do with what happens when the finish is inevitably scratched or chipped down to the secondary surface. My understanding is that the damage is not repairable and cannot be polished out as with stainless steel. Additionally, the surface and subsurface materials may contrast and highlight an otherwise minor scratch.


Thanks John MS for your post.
I found an interesting post on this forum about "repairable" and "Non-repairable" scratch resistant finish.

If I remember it correctly, the "tegemented" watch is very scratch resistant but cannot be repaired once there is an "egg shell" crack on it.

I am NOT sure about the other scratch resistance finishes...

The purpose of our discussion is to pass the knowledge from the well-verse member to the newbie of this forum...
Please do post if you have info ...


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## South Pender

This is a very useful thread! I've been wondering about how the Seiko finishes like Diashield compare with the Citizen and Casio ones. In particular, though, I would be very interested in where the Brightz finish on that line of Seiko watches falls on the continuum of hardness and scratch-resistance. I've read that it consists of some alloying of the titanium to improve hardness, but I assume it also has some kind of coating. Can anyone provide more detail on the Seiko Brightz finish?


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## Rapt

Some additional comments... DLC covers a huge range of quality and hardness the best stuff is as hard as diamonds or possibly harder. Its generally much overpriced as a watch "feature". Applied properly it won't flake, chip or peel, but it will follow the contour of the underlying metal, to the point that its possible to dent the substrate and have the coating conform as the dent happens without damaging the coating. So its not a panacea, but can be a great thing.

Titanium is rarely used over in a pure form. Most commercial grades are alloyed with a variety of other materials which means that strengths and hardness vary considerably. Without knowing the actual grades its almost impossible to make any sort of useful generalizations about it, beyond that its lighter and stronger (for its weight) than many grades of steel.


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## herbolaryo

*"Friction and wear property improvement by surface modification: effect of electroless plating film and DLC coating"*

http://www.emeraldinsight.com/Insight/viewContentItem.do?contentType=Article&contentId=874589

This article I found states that...
_"DLC_ coating film has a _Vickers_ hardness number of 3000-5000"

However, the info is incomplete because I have NOT seen the entire article. 
If you have this in your library, please do post...

It is known that the metal where you coat the DLC also affects its hardness. 
My assumption is that titanium is a softer metal as compared to stainless steel (on the Vicker's scale). 
Therefore, a DLC-coated titanium is softer/less scratch resistant than DLC-coated stainless steel. 
Titanium is used becaused it is a lighter metal. 
However, I don't know how a Titanium alloy match-up with the hardness of a DLC-coated stainless steel.

I emailed citizen japan about the Vicker's hardness of their DLC-coated titanium. I never received a response.
I am assuming the lack of an "objective" measure of hardness puts hype to any product.

Are "DLC-coated", "Titanium", "Tegemented", "PVD" ......etc.... ALL exaggerated claims? :think:

Unless we know a Vicker's hardness scale "number" on them.... we can't compare which one has better scratch resistance.


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## vzwdataguy

Okay, this is awesome. I called a shop that does DLC titanium coating for automotive and medical applications and they said that they can also do watches. The cost for a load in the DLC coating machine is $1000 and the tray is 18"x24." If they can load your watch and bracelet links in there with similar sized pieces (the pieces have to be similar sized to get an even coat from the high temperature vapor deposition on the electrically charged metal - hope that's close to right) it could drop the cost down to about $100 per watch. I'm thinking about doing this with an old all-digital MR-G. Note, the piece will come out blackened, so you have to think about the difference in color schemes. The piece will come out with about 4 microns thickness of DLC and will reassemble perfectly and will have 3600 Vickers surface strength. More info here: http://www.applieddiamondcoatings.com/adc_pdf/Diamomed_Properties2007.pdf


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## ronalddheld

Do you have to send the watch case(minus movement and display) and bracelet, or just the watch and bracelet?


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## vzwdataguy

All pieces, links, screws would need to be disasembled prior to sending. They don't have a watch specific service.


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## fstshrk

I have a watch with a duratect coated bracelet and a DLC coated bezel from Citizen.

Had for over 2 months, wearing it every day. So far both the duratect bracelet (Ti) and the bezel have not had a scratch. Compared to this, when I wear my stainless steel bracelet watches, there is usually lots of scratches on the bracelet due to my desk diving job.

These two coatings WORK. There is no doubt in my mind about this.


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## dal_sing

Thanks - the "coating" info & discussion has cleared up many questions.


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## sfsasmith

vzwdataguy said:


> Okay, this is awesome. I called a shop that does DLC titanium coating for automotive and medical applications and they said that they can also do watches. The cost for a load in the DLC coating machine is $1000 and the tray is 18"x24." If they can load your watch and bracelet links in there with similar sized pieces (the pieces have to be similar sized to get an even coat from the high temperature vapor deposition on the electrically charged metal - hope that's close to right) it could drop the cost down to about $100 per watch. I'm thinking about doing this with an old all-digital MR-G. Note, the piece will come out blackened, so you have to think about the difference in color schemes. The piece will come out with about 4 microns thickness of DLC and will reassemble perfectly and will have 3600 Vickers surface strength. More info here: http://www.applieddiamondcoatings.com/adc_pdf/Diamomed_Properties2007.pdf


 did you ever send you watch in - if yes were you happy with the result?


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## sfsasmith

did you ever send your watch in - if yes were you happy with the result ??


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## drdoom

As far as Ti and DLC I'm kind of unimpressed. Here's my 5 month old MRG 8100 that's made of Ti and treated in DLC. I don't remember when it happened. I've have stainless steel watches that I've beat up and have never had them dent and I baby this watch. Makes me a bit angry. Wonder if I can have it fixed.


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## Catalin

drdoom said:


> As far as Ti and DLC I'm kind of unimpressed. Here's my 5 month old MRG 8100 that's made of Ti and treated in DLC. I don't remember when it happened. I've have stainless steel watches that I've beat up and have never had them dent and I baby this watch. Makes me a bit angry. Wonder if I can have it fixed.


IMHO Casio is not the best at that but I am a little surprised by the color in your pictures - the Casio 'stock pictures' always suggest a much 'darker' color for the DLC ...

Anyway if the titanium below the coating is not a very high grade one (with a lot of vanadium) the actual resistance to major dents is not impressive, since the material will 'crack' in the titanium and not at the coating level ... the same has been described for Seiko's Ti + Diashield and I have no reason to believe that Citizen is much better (even if I have to admit that some of the Citizen versions just feel a LOT heavier than for instance the Ti that is used in my Seiko SBQJ015).


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## ronalddheld

Doesn't the quality depend on the thickness of the layer and the mixtures of diamond phases?


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## drdoom

I can't seem to quote from my phone but in response to Fstshrk, yes my stainless steel bands have been scratched on table surfaces but these were minor and have been buffed out, I have yet to dent a stainless steal watch the way I have my MRG.

"Catalin" yes the Casio stock photos make it seem as the watch is darker than what it really is. It's the lighting and the way it's photographed, the first thing I thought when I recieved my watch was "hey they sent me the wrong color" 
A while back I posted a few photos of my MRG and At first, under regular light it appears black and later on in the post the watch was photographed under natural sunlight and seems gray. See here:

http://forums2.watchuseek.com/showthread.php?t=352069

As far as denting my Ti and DLC watch I'm kind of shocked. It does how ever hold up well to scratches and have yet to find one. One quick question, what can dent Ti and DLC? I mean that's as strong as it gets on that scale. Beleive it or not the only thing I ever remember bumping the watch into was the corner of a wood self. But I didn't think anything of it as since it was wood.


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## Catalin

drdoom said:


> I
> ...
> "Catalin" yes the Casio stock photos make it seem as the watch is darker than what it really is. It's the lighting and the way it's photographed, the first thing I thought when I recieved my watch was "hey they sent me the wrong color"
> A while back I posted a few photos of my MRG and At first, under regular light it appears black and later on in the post the watch was photographed under natural sunlight and seems gray. See here:
> 
> http://forums2.watchuseek.com/showthread.php?t=352069
> 
> As far as denting my Ti and DLC watch I'm kind of shocked. It does how ever hold up well to scratches and have yet to find one. One quick question, what can dent Ti and DLC? I mean that's as strong as it gets on that scale. Beleive it or not the only thing I ever remember bumping the watch into was the corner of a wood self. But I didn't think anything of it as since it was wood.


Obviously even wood can dent titanium - the simple 'hardness scale' does not automatically mean that an object lower on the scale will not dent (or break) some material higher - it will just mean that the 'scratches' on the tougher material will be (far) smaller than on the other - and I guess that the shock that dented your watch has left a sizable/bigger dent in the wood too ;-) (another famous example is a ball of lead - Mohs hardness 1.5 - that still breaks a normal glass window - around 7 on the same Mohs scale).


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## rex

*Citizen's Duratech coating sure leaves little to be desired, IMO.>*

Whatever method Citizen claims how it's applied is pretty much useless on stainless steel. Perhaps on their titanium models, it's more robust.

Here's what the bottom of my Chronomaster's bracelet looked like with a little over 2 years of wear before I sent it in to have refinished.


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## putnam dan

DLC over a softer core can result in 'eggshell' damage. Essentially the substrate compacts under the coating causing the cracking type of damage seen here.


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## drdoom

Catalin said:


> Obviously even wood can dent titanium - the simple 'hardness scale' does not automatically mean that an object lower on the scale will not dent (or break) some material higher - it will just mean that the 'scratches' on the tougher material will be (far) smaller than on the other - and I guess that the shock that dented your watch has left a sizable/bigger dent in the wood too ;-) (another famous example is a ball of lead - Mohs hardness 1.5 - that still breaks a normal glass window - around 7 on the same Mohs scale).


roger that, makes sense.


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## fstshrk

Duratect on my Skymaster Pro Navihawk has been amazingly robust.
The bezel on this watch is DLC and it is also equally robust. Several years of wear now and pretty much scratch free.


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## Catalin

*Re: Citizen's Duratech coating sure leaves little to be desired, IMO.>*



rex said:


> Whatever method Citizen claims how it's applied is pretty much useless on stainless steel. Perhaps on their titanium models, it's more robust.
> ...


I believe many of the high-end steel models mainly have a PTIC coating, which is 99% not for extreme hardness but instead to avoid Nickel allergies ... however I would say that the look on your bracelet after refinish is VERY promising - many materials will never look as good as originally no matter what you do ...


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## Citizen V

Catalin said:


> IMHO Casio is not the best at that but I am a little surprised by the color in your pictures - the Casio 'stock pictures' always suggest a much 'darker' color for the DLC ...
> 
> Anyway if the titanium below the coating is not a very high grade one (with a lot of vanadium) the actual resistance to major dents is not impressive, since the material will 'crack' in the titanium and not at the coating level ... the same has been described for Seiko's Ti + Diashield and I have no reason to believe that Citizen is much better (even if I have to admit that some of the Citizen versions just feel a LOT heavier than for instance the Ti that is used in my Seiko SBQJ015).


This had been bothering to me as well.
I have two (pre-owned) Citizens with Duratect and the coating has held up amazingly. But both have little chips in the case from previous owners, something I have not seen in any ss watches I've had (even those which were extremely beat up). I thought it may have just been bad luck or because of how they were used but I guess your post answers that question.


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