# Steel hardening process: Tegiment Vs Ice Hardening Vs Bremont hardening process



## umarrajs (Oct 18, 2012)

I have often wondered about the various steel hardening process used by Sinn, Damasko and Bremont. Would appreciate comments on what it comes down to day to day use of a watch. Which one looks better, can take blows/nicks better and how do they compare with DLC :-s
I know the Henckel knives I use are Ice Hardened so probably that process will take the abuse best?

Thanks.


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## CMSgt Bo (Feb 12, 2006)

I hate to kill a thread, but everything you ever wanted to know about Sinn/Damasko/Bremont's steel hardening process has already been discussed at length and can be summed up on post number 23 here: https://www.watchuseek.com/f24/316l-vs-submarine-steel-362046.html


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## Juha (Feb 12, 2006)

umarrajs said:


> I have often wondered about the various steel hardening process used by Sinn, Damasko and Bremont. Would appreciate comments on what it comes down to day to day use of a watch. Which one looks better, can take blows/nicks better and how do they compare with DLC :-s
> I know the Henckel knives I use are Ice Hardened so probably that process will take the abuse best?
> 
> Thanks.


This is one point or actually two points from the Sinn website that I have not seen discussed here:

"In 2003 the ice hardening method was replaced by TEGIMENT Technology for two reasons: firstly because the corrosion resistance caused by the ice hardening deteriorated on contact with perspiration and salt water, and secondly because the treated parts had a strong tendency to become magnetised, which can have a negative impact on movement components which are vital to the watch's correct functioning."


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## CMSgt Bo (Feb 12, 2006)

Juha said:


> This is one point or actually two points from the Sinn website that I have not seen discussed here:
> 
> "In 2003 the ice hardening method was replaced by TEGIMENT Technology for two reasons: firstly because the corrosion resistance caused by the ice hardening deteriorated on contact with perspiration and salt water, and secondly because the treated parts had a strong tendency to become magnetised, which can have a negative impact on movement components which are vital to the watch's correct functioning."


The remedy for the second concern was eloquently explained by member TrickTock in the above referenced post:

Damasko was smart to patent their choice of steel alloy for all watch case applications. They use Cronidur 30 (X30CrMoN15 1). They did not invent this steel, nor did they develop its ice hardening process. But they were brilliant in finding novelty in order to secure a patent. Here is their explanation of novelty from their US patent:

_"these materials have heretofore been regarded by experts as unsuitable for the manufacture of wrist watches, due to the fact that such steels are highly magnetizable, especially by external magnetic fields, so that they function as permanent magnets whose magnetic field strongly impairs the highly sensitive clockwork of a wrist watch. The invention is based on the realization that the aforementioned hardenable steel surprisingly is suitable for wrist watch cases, and especially if in the interior of the case a ring or plate enclosing the clockwork is made of a diamagnetic metal."_

So Damasko is saying that nobody thought to use this type of steel because it can become magnetic and screw up the movement. They solve this problem by putting in a diamagnetic inner cage around the movement. This might seem obvious to a WIS in hindsight, but probably was quite impressive to the patent examiner.

The Damasko ice-hardening is a complex process. I haven't yet seen it described anywhere on the web, so here it is: First the metal is heated to above 1000°C, then rapidly quenched to room temperature in oil. This is followed by deep freezing at - 80 °C for 1 hr, then tempering for several hours at 160°C to give hardness >710 HV. The Pitting Resistance Equivalant is 30 points which is similar to 316L. The nickel-free composition is great for people with allergies.

So what about Bremont watches? Here is a quote from QP magazine: http://www.jurawatches.co.uk/PDF/bre...ingyarnQP1.pdf

_"Furthermore, all the cases and buckles are brought back to England to be treated for hardness with B-EBE2000 technology, a process used on the turbine blades of jet engines. The cases are heated to high temperatures and carbon diffusion is used to increase the overall underlying hardness of the case to 1,200 Hv on the Vickers scale (normal watch-grade stainless steel is more like 280 Hv in hardness). Argon electron ions then prepare the surface of the case followed by a metallic ceramic coating at temperature, bringing the case hardness up to 2,000 Hv - the same hardness as sapphire crystal._

Based on this info, Bremont is kolsterizing, then plasma spray coating. Since this is done in England, they are probably using Poeton Apticote 800/24. This is a tungsten carbide and cobalt coating applied with an argon plasma torch. That gives hardness of 2000HV, and is used on jet turbine blades. Poeton does work for Airbus and Rolls Royce.


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## Juha (Feb 12, 2006)

CMSgt Bo said:


> The remedy for the second concern was eloquently explained by member TrickTock in the above referenced post:
> 
> Damasko was smart to patent their choice of steel alloy for all watch case applications. They use Cronidur 30 (X30CrMoN15 1). They did not invent this steel, nor did they develop its ice hardening process. But they were brilliant in finding novelty in order to secure a patent. Here is their explanation of novelty from their US patent:
> 
> ...


Woops, I read that post, but still somehow missed the point. Thanks for correcting me!

So the quote I posted from the Sinn website just means that you cannot have Ice hardened case without magnetic field protection. So for example fully Ice hardened U1 could be problematic construction, but fully tegimented U1 is not.

Based on that I assume that ice hardened case without magnetic field protection would have significantly worse anti magnetic properties than a normal watch case. You would have to have it demagnetized more often in normal use.

Also there would be no problems with first generation Sinn 756 models with Ice hardened cases since the watch uses magnetic field protection technology.

Or did I get it wrong?


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## umarrajs (Oct 18, 2012)

No problem.
Thanks for the link.


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## IronDave (Jul 27, 2011)

I hate to reply to such an old thread and probably won't get a response but...

Having considered CMSgt's response --> does this mean that a Damasko owner should be careful to keep the watch separated from other watches, i.e. it could magnetize your other cases/movements?

Cheers,
Dave


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## rationaltime (May 1, 2008)

IronDave said:


> I hate to reply to such an old thread and probably won't get a response but...
> 
> Having considered CMSgt's response --> does this mean that a Damasko owner should be careful to keep the watch separated from other watches, i.e. it could magnetize your other cases/movements?
> 
> ...


I guess that a Damasko case might become indirectly magnetized,
but only weakly. Theoretically that could affect other watches,
but I guess the effect would be very small. I don't worry about it.

Thanks,
rationaltime


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## Vig2000 (Jul 5, 2012)

I also apologize for resurrecting an older thread, but does anyone have any thoughts to offer regarding Dievas' 6Steel, especially as compared to Sinn, Damasko, and Bremont's hardening processes?


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## rationaltime (May 1, 2008)

Where is our resident metallurgist when we need him?

It appears the initial treatment of those Dievas cases is similar to
Kolsterizing or Tegimenting. It seems Dievas is not saying what goes
into the surface layer. That makes it difficult to compare to others.








The Damasko hardened cases use a different steel and a different
process that does not apply to 316L stainless steels. I do not try
to compare. My Damasko watches are not showing any scratches.

My Sinn U1 case is not Tegimented, and it also does not have any marks.
There is no such thing as the perfect material. Even coated carbide tools
wear out and chip. These watch cases seem to hold up well to every day
wearing. If you like one of the Dievas watches I think you should go for it.

Thanks,
rationaltime


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## CMSgt Bo (Feb 12, 2006)

It seems both Dievas and Damasko share the same vulnerability to magnetism. Or maybe it's just a coincidence they both utilize a Faraday Cage between their cases and their movements.


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