Elinvar vs. Nivarox vs. Parachrom

[chris russell]

A few people have posted inquiries about the new Parachrom Blu hairspring Rolex is installing in new watch designs as they appear, (first in the Daytona, then in the Milgauss, then the DSSD, the GMTIIc, and the new Ceramic Subs). I spent a little time looking into the characteristics of Parachrom in comparison with two other popular alloys used over the years. These alloys were designed to solve two problems with the earlier blued steel hairsprings: thermal instability and magnetic susceptibility, (plus a third problem with steel; rusting).

Steel has a relatively large thermal coefficient of modulus of elasticity. That is, its 'springiness' varies with temperature, necessitating complicated and only partially effective compensation schemes in the balance assembly.

Steel is also strongly affected by magnetic fields, leading to distortion and magnetization which drastically affect timing.

Among the first alloys to minimize these issues was Elinvar, a mixture of 59% iron, 36% nickel and 5% chromium, invented in 1919 by Charles Guillaume. The chromium reduced but did not eliminate the other two (ferrous) metal's susceptibility to magnetization, and the alloy's elasticity varies very little with temperature. This made possible accurate watches without complex schemes for thermal compensation, and providing watches with 'anti-magnetic' properties for the first time.

An improved alloy, Nivarox, came along in around 1933, invented by Dr. H. C. Reinhard Straumann, consisting of about 45% cobalt, 20% nickel, 20% chromium, 5% iron and smaller percentages of titanium and beryllium. The exact proportions of the metals in the alloy varies with the specific application. Although cobalt, nickel and iron are all ferromagnetic metals, the high proportion of chromium further damps the alloy's response to magnetism, better than Elinvar, though there is data showing Nivarox's thermal coefficient of modulus of elasticity is not quite as good as Elinvar's, and possibly not quite so predictable in production.

Both alloys have good resistance to magnetic fields, though not complete, due to their heavy proportion of ferrous metals. In 2000, Rolex, after several years of experimentation, introduced another alloy, 'Parachrom', this time made of entirely non-ferrous metals, (85% niobium and 15% zirconium), which was carefully mixed in proportion to deliver a nearly zero thermal coefficient of modulus of elasticity. Although both of these metals are strongly resistant to corrosion, Rolex found that by deliberately coating the alloy with a thin, (roughly 100 Nm), layer of oxide, coincidentally a beautiful blue color, its stability with time was even further enhanced. Thus in 2005, the Parachrom hairsprings turned blue, and Parachrom Blu was introduced.

This new alloy appears to all intents to be the finally almost 'perfect' hairspring material; completely insensitive to magnetic fields, showing almost no response to varying temperatures and virtually impervious to long-term corrosion or change in characteristics. In addition, Rolex claims that it is far more stable with mechanical shock than the older alloys.

I have and have had a few Rolexes with this Parachrom hairspring, and I can report that they are almost spookily stable with position, (perhaps due as much to the Breguet overcoil), with daily use showing almost no 'drift' in timing over many months. I subjected one of my Daytonas to freezing temperatures with no discernable change in timing. Admittedly, my Rolex with the older Nivarox hairspring is almost as good in these respects, but the Parachrom seems just that much better.

To me, this goes a long way toward proving Rolex is committed to staying at the leading edge of mechanical watch accuracy and reliability.

Incidentally, as most of you know by now, the latest issue of 'Watchtime' (with the green-dial Rolex Sub on the cover), contains a fascinating article which among other things delves into the very careful alloying process Rolex performs in its own factory, to produce the metal for these hairsprings.

I welcome comments or possible corrections if any factual errors crept into my post. Thanks.

[tkc324]

Wow... very informative~ Thanks~

[Jim232118]

Great Post!

[Tools]

Patek uses a silicon based, completely non-metallic/non-magnetic Spiromax hairspring.......

[chris russell]

Originally Posted by Tools

Patek uses a silicon based, completely non-metallic/non-magnetic Spiromax hairspring.......

of one watch, and silicon may turn out to be a wonderful material as well. It is certainly non-magnetic, they seem to have made sure the spring expands and contracts concentrically, and silicon may have a truly minimal response to temperature variations. I'd welcome the opportunity to wear a Patek with this silicon technology for long enough to determine if it performs as well as the 3135 or 4130 with the Parachrom Blu. (That would be a tall order). But Patek has deliberately made the technology virtually unavailable to 'regular' people who aren't personal friends with Thierry Stern and also happen to have a very large financial portfolio. Meanwhile, Rolex has probably shipped hundreds of thousands of watches with the Paracrom and Parachrom Blu hairsprings, and I've been able to afford several of them, and have been able to see the performance with my own eyes.

I know Rolex was and probably still is involved in the consortium of watch companies studying and developing silicon parts in the escapement, including the hairspring. I surmise they thought they were obtaining a better performance/reliability/repeatability package with the Parachrom Blu. It's just my opinion, but I would trust Rolex's judgement on that kind of thing ten times out of ten over Patek's.

It's also just an opinion on my part, but I like the idea of a metallic alloy solution to the hairspring problems of temperature, magnetism and corrosion. I mean, if we are going to build watch mechanics out of silicon, etched like electronic wafers, how far are we from just going the whole way to a watch with a battery in it?

[padi56]

Originally Posted by Tools

Patek uses a silicon based, completely non-metallic/non-magnetic Spiromax hairspring.......

Have to agree with Larry and the Parachrom was developed in the beginning with Patek before they went on to develop there own.Sure the parachrom on paper might have a tiny advantage over the Nivarox ones that have powered the majority of the Swiss watch world for the past few decades.But in the real world to the average watch wearer I would doubt if they would find little or no difference whatever hairspring was in the case.So if you don't wear your watch dial down with the back off and dangle a magnet over it you should have little problems with accuracy.Now good regulation thats where good accuracy comes mainly from, you could have any hairspring in case but if watch is not regulated correctly then accuracy will not be good.There are many many watches Rolex and others with Nivarox hairsprings running for decades and still extremely accurate as Rolex has been for the last 50 odd years.And if one is a second or so better or worst than the other does it really matter.They all have to pass the same COSC test no matter what spring is in case to be called a chronometer.Now I applaud Rolex for now being almost all 100% in-house built they still out source the main-springs.

[chris russell]

Originally Posted by padi56

Have to agree with Larry and the Parachrom was developed in the beginning with Patek before they went on to develop there own.Sure the parachrom on paper might have a tiny advantage over the Nivarox ones that have powered the majority of the Swiss watch world for the past few decades.But in the real world to the average watch wearer I would doubt if they would find little or no difference whatever hairspring was in the case.So if you don't wear your watch dial down with the back off and dangle a magnet over it you should have little problems with accuracy.Now good regulation thats where good accuracy comes mainly from, you could have any hairspring in case but if watch is not regulated correctly then accuracy will not be good.There are many many watches Rolex and others with Nivarox hairsprings running for decades and still extremely accurate as Rolex has been for the last 50 odd years.And if one is a second or so better or worst than the other does it really matter.They all have to pass the same COSC test no matter what spring is in case to be called a chronometer.Now I applaud Rolex for now being almost all 100% in-house built they still out source the main-springs.

The fact that Patek has a silicon hairspring? Yeah, nobody was disputing that, though it's only used in a few pieces of a multi-tens-of-thousands-dollar watch, essentially unavailable to the public. Larry, (and you?), seem to be saying that the Parachrom Blu hairspring is mostly useless, no big deal, 'overhyped', to quote an earlier post of Larry's. Well, if a hairspring that eliminates magnetism as a possible problem, improves temperature stability, essentially eliminates corrosion as a problem, improves shock resistance, and at least in my experience markedly improves the timing stability of an affordable watch, is 'overhyped' and no big deal, then what does that make the silicon hairspring in that hugely-overpriced safe-queen of a Patek, that maybe does the same things for ten times the money?

Maybe I'm missing the point here somewhere... Is that what this forum exists for, to slag, criticize, shoot down and minimize the efforts by Rolex to make a better product, especially by the Moderators of the Forum? I must be living in some kind of Bizarro upside-down world. Or at least somebody is.

[Tools]

Yes, you are missing the point.. You also seem to be taking a personal attack because others do not share your desire to attribute magical qualities to a simple spring..

The attributes of the parachrom hairspring are only attributable to the hairspring itself......... nothing else...

The Nivarox hairspring has a very slight percentage of ferrous metal, and so it would take a tremendous magnetic field or huge temperature fluctuations to affect one. The Parachrom has improved on these already excellent characteristics. But in either case, magnetism, temperature, shock, or other extremes would affect the other many working components long before the affects were felt at the hairspring... You state, or imply that a Parachrom "...eliminates magnetism as a possible problem...", and that statement is simply incorrect beyond the hairspring itself.. The Milgauss movement is the only one made with non-ferrous metals where possible throughout the movement, and still must employ a Faraday cage and no-date window to keep out spurious magnetic flux.

Nobody has said that the development of the Parachrom was not an achievement on Rolex part. What is said is that the Parachrom is still just a hairspring.... It is not a leap forward in the engineering or technical advancement of the lever action mechanical time-piece. So far, based on the many, many discussions on TRF and other Forums, the Parachrom equipped movements are not significantly out-performing non parachrom equipped movements, if at all.

I simply added to your post by stating that Patek was going towards a silicon based technology... perhaps it is the future.. Or perhaps TAG's new no-hairspring design that actually uses magnets to produce the familiar balance oscillations ... What does that do for anti-magnetics.?? Even Seiko uses it's own proprietary non-magnetic hairspring.......

Your take on additional information in "your" thread is skewed towards antagonism and demonstrates a closed mind and "fan boy" mentality towards Rolex rather than the science of horology and the acknowledgements of achievements within the entire community.

[nickriebe]

Think im going to save this post... so much info!

[Joey007]

Thank you. It's very informative.

[Roxas]

Many thanks for the very informative post.

Regarding shock resistance, is the Parachrom hairspring 10 times better than the Nivarox hairspring?

Rolex claims that it's 10 times better than traditional hairsprings.

[chris russell]

Originally Posted by Roxas

Many thanks for the very informative post.

Regarding shock resistance, is the Parachrom hairspring 10 times better than the Nivarox hairspring?

Rolex claims that it's 10 times better than traditional hairsprings.

I'd love to know the particulars of what that means myself. Does it mean the Parachrom hairspring will not permanently deform with an impact less than ten times what would permanently deform a Nivarox hairspring? How much impact would it take to permanently deform a Nivarox hairspring? Would it be enough to permanently deform the watch case and the gears inside? Would ten times that much impact turn the entire watch, (except the hairspring), into shrapnel? I don't know the answer to these questions, but I'd love to read more if Rolex, (or anyone), would grace us with the data.

I know I've occasionally given a watch a heck of a knock by accident, like dropping it from chest height onto a tile floor. I remember it changed the timing a bit. Was the change in timing a result of the hairspring undergoing a permanent deformation, or was it just the regulator shifting a bit?

Another thing I've had happen a couple of times is the hairspring moving enough inside the case to have a coil get 'stuck' over the regulator pins and start gaining twenty minutes a day. I am reasonably sure that was from impact, not even necessarily noticed at the time. But I can tell you it is a PITA to have to take the watch in to be serviced to unstick the hairspring.

In any event, Rolex doesn't use regulator pins on their automatic watches, so the chance of a coil getting 'stuck' from an impact is pretty close to zero, but I guess impact resistance is something you could still consider an advantage.

[Arrgo]

Great info Chris, thanks very much for taking the time and spending the effort on researching this. Despite the opinions good, bad or indifferent, it was a very interesting read

[Welshwatchman]

Perhaps the thread should have been posted in the reference section as an mini essay about hairsprings as opposed to the General Section where a debate over whether the Parachrom Blue hairspring was a worthwhile development or a waste of time could be entered into.

Me, I just like the shiny shiny.