# Looking for a hardened watch? Why DLC rocks



## allanvalle (Oct 13, 2006)

I scratched up my Citizen Skyhawk professional the other day to prove that it is 99.999 percent scratch-proof to just about everything except for a diamond of course. DLC stands for diamond like carbon. So here are the photos of my keyed watch. Don't try this on non-DLC watches! 

The keys are bronze and steel.























































My DLC collection



















From wikipedia: The hardest, strongest, and slickest is such a mixture, known as tetrahedral amorphous carbon, or _ta-C_. For example a coating of only 2μm thickness of _ta-C_ increases the resistance of common (_ie._ type 304) stainless steel against abrasive wear; changing its lifetime in such service from one week to 85 years. 


The link: http://en.wikipedia.org/wiki/Diamond-like_carbon


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## Ron Engels (Apr 29, 2005)

Hi Allenvalle,

Very nice collection and an interesting post.
I'm afraid I don't quit understand it however. Could you please explain what exactly you've done to scratch the clasp, and what exactly you are trying to prove? Did you damage the clasp or not?


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## allanvalle (Oct 13, 2006)

*Nope not a single scratch*

Hi Ron,

I basically keyed the clasp with a bronze key(the baldwin) and a SS key to test the "hardness" of DLC. This was done in response to a foumer who thought I had just taken a photo of before and after and switched the order. Here'e the post: http://forums.timezone.com/index.php?t=msg&goto=2963825&rid=44235#msg_2963825

DLC is actually harder than both of those keys and has actually grounded down the keys a little bit. The letters formed are from the keys being ground off. It works as DLC should. The only way to etch into DLC is by using a material harder that the coating and that would be a diamond. I was in disbelief before my first DLC watch the MR-G 7100. But when I tried to etch that as well, not a single scratch. Ever since I have been sold on DLC's high-tech hardness. I hope this makes sense


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## Ron Engels (Apr 29, 2005)

*Re: Nope not a single scratch*



allanvalle said:


> I hope this makes sense


Yes it does! Thanks for the explanation.
One more question if you don´t mind.
I´m convinced now that it is well protected against scratches. But does it also help preventing dings and other small imperfections, that are not caused by ´scraping´ (contact by objects moving along the surface) but by 'hammering' (contact with objects moving straight on to the surface). I hope you understand what I'm trying to ask ;-). And obviously please don't try this on your watches!


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## allanvalle (Oct 13, 2006)

*This is my take on it*

Ron, My MR-G 7100 is almost a year old and it has no dings in it. Its only kryptonite that I have encountered is: DLC is able to scratch DLC. I found areas in the DLC Ti bracelet where heavy friction must have worn down the DLC but it was DLC on DLC so it makes sense. Only 2 areas to be exact on the folding clasp.

I do know that DLC has a very low coefficient of friction so its like Teflon in a way. I'd assume any heavy impact would just glance off of the watch since it is very slick. Here's a graph of its coefficient of friction versus other materials: http://www.bekaert.com/bac/Products/Diamond-Like Coatings/Coating Types/Coefficient of Friction.htm

I have banged the watch heavily on doorknobs, metal railings, lawn mowing equipment, and recently someones sideview mirror at a parking lot and I've yet to see any dings. But I'm sure any strong impact involving say a hammer would dent a thin sharp angled corner of the watch but maybe not its bezel or thicker parts of the case.


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## alpine003 (Jul 6, 2007)

Very good info but do all the Citizen DLC watches have sapphire crystals on them?

I just knicked the crystal on my Citizen the other day when riding my bike coincidentally.


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## allanvalle (Oct 13, 2006)

*Saphire*



alpine003 said:


> do all the Citizen DLC watches have sapphire crystals on them?
> .


Yes, both Citizens with DLC have saphire crytsal as do both Casio MR-Gs.


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## mchomicz (Apr 28, 2006)

I was quite excited when I first saw your photos thinking I finally found a titanium watch (CITIZEN PMV65-2242; one of those you have) able to stand up to the 'rigors' of my daily life. Alas - my brand new watch remained scratch free for a whooping 3 days...

I'm not a coal miner or a construction worker mind you. And I don't work with diamonds, either ;-) I don't abuse my watches (for example I don't wear metal watches to the gym where they might get bumped on free weights etc) but I don't baby them, either. I just wear them.

So how did I manage to scratch a Carbon Like Diamond protected watch? I was moving a baby stroller from one car trunk to another with one hand while holding car/house keys on an aluminum key chain in the other. As I was performing this highly demanding maneuver - I switched hands and as I was doing so - a key or key chain come in contact with the clasp of my DLC treated watch resulting in a scratch. Not on a key or the key chain mind you but rather on the clasp.

While I have no illusions that short of sapphire crystals - there is no such thing as a scratch proof watch component (technically sapphire is not scratch proof, either; but for all intents and purposes - it is) I was quietly hoping for more than a few days of scratch-free watch from a product that has the word 'diamond' in its name...

Now granted - a week later that scratch remains the only one on the watch and it is very small. So perhaps I was just extremely unlucky. Still - goes to show that there really is not such thing as a scratch proof bracelet or case (at least not made out of metal). I'm told ceramic watches are pretty hard to scratch. Anybody tried those?

BTW - I am not questioning in any way your experiment. I believe that you did in fact key the watch. But I guess in 'real life' - scratches on watches happen in ways that have got to be different from a 'controlled exercise' involving scratching a watch with a key (or a screw driver) with force just sufficient to leave a mark (created by key / screw driver material rubbed off on the watch) but not so strong as to damage the watch. I bet if one tried to really jam that screwdriver into the clasp though - results would be less than pretty ;-)

Michael


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## Tragic (Feb 11, 2006)

mchomicz said:


> I was quite excited when I first saw your photos thinking I finally found a titanium watch (CITIZEN PMV65-2242; one of those you have) able to stand up to the 'rigors' of my daily life. Alas - my brand new watch remained scratch free for a whooping 3 days...
> 
> I'm not a coal miner or a construction worker mind you. And I don't work with diamonds, either ;-) I don't abuse my watches (for example I don't wear metal watches to the gym where they might get bumped on free weights etc) but I don't baby them, either. I just wear them.
> 
> ...


I'll bet you a nickel against 5 bills a Damasko wouldn't have scratched b-)


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## mchomicz (Apr 28, 2006)

Tragic said:


> I'll bet you a nickel against 5 bills a Damasko wouldn't have scratched b-)


I don't gamble - so I don't know if the odds you are suggesting are any good for the Damasko (my guess is that yes). Does Damasko make their cases / bracelets out of ceramics? Or do they use some variation of the technique used by CITIZEN?

Michael


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## mchomicz (Apr 28, 2006)

mchomicz said:


> Does Damasko make their cases / bracelets out of ceramics? Or do they use some variation of the technique used by CITIZEN?


Found the answer to my own question ;-) Interesting. Too bad their watches are not something I'm in the market for...

Michael


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## Crusader (Apr 30, 2005)

As far as protection against scratches go, Sinn's tegiment technology should do very well, too.


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## allanvalle (Oct 13, 2006)

Hi Michael,
What DLC watch was this and pics when you get a chance? Hard for me to believe since all 5 of my DLC watches look BNIB and I'm rough on them. I'm not calling you a liar, pls dn't take it personal but in 1 yr of abuse my MR-G 7100 looks brand new. Scratches leave a mark that just wipes off as in my pics, from doorknobs, railings, car door, hitting grocery carts, elevator doors, etc.


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## Radio_Daze (Sep 24, 2006)

The only Watches I've heard of that are not supposed to scratch, are the ones that are made of Tungsten. At least they don't on TV when I've seen demonstations trying to scratch them when they are selling them.

But there again, demonstrations on TV shopping channels don't mean much I suppose!:roll:


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## Tragic (Feb 11, 2006)

Radio_Daze said:


> The only Watches I've heard of that are not supposed to scratch, are the ones that are made of Tungsten. At least they don't on TV when I've seen demonstations trying to scratch them when they are selling them.
> 
> But there again, demonstrations on TV shopping channels don't mean much I suppose!:roll:


I owned a tungsten carbide Movado Valor.
Just a beautiful dress watch with a mirror finish everywhere.
Very heavy.
Somehow it picked up 2 very tiny scratches in the bezel.
Don't know what scratched it but I can certainly vouch that they couldn't be polished out by any of the usual cloth methods :-d


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## mchomicz (Apr 28, 2006)

allanvalle said:


> Hi Michael,
> What DLC watch was this and pics when you get a chance?


As disclosed above: CITIZEN PMV65-2242. Sure, I will post a photo when I have a chance. I don't have a reason to make this stuff up - I own the watch and would certainly prefer it did not scratch ;-) But it did. What happened is probably the 'egg shell' effect Damasko web site talks about (very hard few microns sit on top of metal that is significantly softer - titanium in my case). It was probably combination of a fairly small impact along with a scratch. I bet if you bumped that key or screwdriver into the clasp (to simulate an impact of a scratching object) as opposed to simply moving it along the surface - you'd be able to reproduce what happened in my case. My scratch is on an the portion of the clasp that bends 90 degrees - so it's on an edge. Will take a photo for you later.

Michael


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## allanvalle (Oct 13, 2006)

Hi Michael,

 I wore my MR-G 7100 today and I looked at the case and bracelet over with a 15x loupe and I found a minor ding on the clasp where there is an indentation. But the black DLC finish is still intact. So I do agree with you scratches are possible. But I would classify it more as an indentation/ding rather than a scratch on my clasp. When I keyed my clasp I put a lot of force behind it and on any other SS or Ti and that would have caused a rather deep etch of "B4", "AFTR", "LOL", and "DLC". My original point was that its way better than any regular SS or Ti or PVD finish.


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## BOEB (Aug 8, 2006)

allanvalle said:


> I scratched up my Citizen Skyhawk professional the other day to prove that it is 99.999 percent scratch-proof to just about everything except for a diamond of course. DLC stands for diamond like carbon. So here are the photos of my keyed watch. Don't try this on non-DLC watches!
> 
> The keys are bronze and steel.
> 
> ...


Very interesting reading and quite a nice "quartet".
I've been looking to purchase a Citizen PMP56-2933 myself but being located in Belgium/Europe this doesn't seem to be all that obvious.
Can anyone assist on recommending some dealers that sell this model ?
Many thanks in advance !


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## mchomicz (Apr 28, 2006)

allanvalle said:


> pics when you get a chance?


A couple pics below. You can actually see the scratch MUCH better in these closeups than in 'real life' (I don't have a magnifying glass). As you can clearly see - the scratch is very real. It's not some leftover material from the object that come in contact with the watch. You can see where the scratch continues (indentation in the surface continues on; though DLC coating did not pop-off on the entire length of the 'dent').

Michael


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## allanvalle (Oct 13, 2006)

Wow Michael that's an ugly scratch! Looks like the dragon skin failed you there. If that happened to DLC than I would hate to see the same results on SS or plain Ti! From your pics it looks very magnified so hopefully its much smaller to the human eye. Thanks for the pics and be careful next time


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## mchomicz (Apr 28, 2006)

allanvalle said:


> Wow Michael that's an ugly scratch! Looks like the dragon skin failed you there. If that happened to DLC than I would hate to see the same results on SS or plain Ti! From your pics it looks very magnified so hopefully its much smaller to the human eye. Thanks for the pics and be careful next time


Yeah, it looks far worse on the photos than it does in person.

As for being more careful - thanks. I can try. But I wasn't doing anything out of the ordinary when this happened ;-) That was the whole point of my post. While I certainly believe DLC is more durable than plain vanilla titanium - it's no magic bullet. I'm sure it will hold up to life better than many other watches. But eventually - scratches will catch up even with DLC. I guess in my case that 'eventually' came particularly quickly...

Michael


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## Mr5150 (Apr 18, 2009)

What is the non digital Citizen DLC watch in the upper left corner in the pic of 4 watches?

Thanks



allanvalle said:


> I scratched up my Citizen Skyhawk professional the other day to prove that it is 99.999 percent scratch-proof to just about everything except for a diamond of course. DLC stands for diamond like carbon. So here are the photos of my keyed watch. Don't try this on non-DLC watches!
> 
> The keys are bronze and steel.
> 
> ...


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