Pitting on 904L

Vintage Rolex Discussion

Pitting on 904L

Joined: March 8th, 2017, 9:32 pm

October 12th, 2017, 5:15 am #1

Does anyone own a Rolex made of 904L steel that has pitting corrosion? I'm familiar with the technical differences between 904L and 316L, but I'm curious about how differently the metals perform, in terms of corrosion resistance, in the real world. I guess one way to see the difference would be to compare 904L-Sea-Dwellers with their 316L-Submariner contemporaries. Any takers?

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Joined: December 28th, 2015, 4:34 pm

October 14th, 2017, 12:32 am #2

for a crash course in material science and metallurgy of stainless steel

http://www.network54.com/Forum/207593/m ... as+been+my+....

and his other thread

http://www.network54.com/Forum/207593/m ... +steel+are.....
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Joined: November 25th, 2011, 11:35 am

October 14th, 2017, 11:50 am #3

something that I had not answered in my past posts. He wants to know how 904L compares to 316L when exposed to the same oxidants in the environment. I hate it when this subject pops up as I am not too popular for discussing this on the forum!!!!

I must add that I have been offered some 904L Stainless steel Rolex models for my consideration of purchase, where I have opened the backs for general inspection such as condition of the movement and the case as a whole.

I have found that some of these 904L stainless steel models DO HAVE CORROSION & PITTING under the back seals and worse still under the bezel tension ring of submariners. I normally do not buy stainless steel models unless they are at a price where I can service them for a feasible resale value. I cannot keep them even if I wanted to, as I work short term in differnt parts of the globe and not being able to carry a collection with me (as I would have to always pay customs duties). By now customs officers would know me too well to be taxed like a sitting duck waiting to be hunted!!!! LOL!!!!

I have the following link on the former Avesta Sheffied (now known as outokumpu) site which has a corrosion table of different grades of stainless steel versus different chemicals and how they resist or fail against exposture of varying chemicals. For example if one wants to compare how good two different grades of stainless steel resist corrosion/pitting attacks against hydrochoric acid then the following will show the differences;

http://steelfinder.outokumpu.com/corros ... 1448799902

In that table you can click on whatever chemicals are listed and can make similar comparisons,

Incidently there is a nice story on some """Happy""" owner experiencing a wonderful horror on his 904L Seadweller HEV on;

https://www.rolexforums.com/showthread.php?t=190495

Hope this has answered your question!! Good Luck!!!
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Joined: March 8th, 2017, 9:32 pm

October 14th, 2017, 9:43 pm #4

Thanks, both of you. Karl -- yes, that's the question I'm interested in: how differently do 904L and 316L actually perform, in terms of corrosion resistance, in the on-the-wrist environment?

There's no shortage of information about how 904L and 316L differ on measures like PREN. Nor is there any question that 904L, like 316L, is susceptible to corrosion in environments that watches often encounter, such as ambient-temperature seawater. Rolex's use of 904L simply lowers the chances, to a level acceptable to Rolex, that a watch will experience pitting. And I'm wondering what that level is.

People who inspect a lot of watches are probably in the best position to answer this question. I've looked at photos of HQ Milton's inventory, for example, to compare 904L Sea-Dwellers with 316L Submariners of the same era. Unfortunately, there aren't a lot of data points because HQ Milton typically doesn't post photos of 904L watches with their casebacks removed. But the available photos suggest that 904L watches, on the whole, exhibit significantly less pitting than 316L watches in their first 30 years. (If perchance Jacek notices this thread and wants to weigh in, I'd be very interested to hear his perspective.)

I think this issue is interesting not only for consumers who want to use a beloved Rolex sports watch for the purposes for which it was ostensibly intended, but also as a way to judge Rolex's "authenticity" as a brand. Rolex could solve the corrosion problem altogether by using titanium, for example, but it has chosen not to do so.

Regards,

David
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Joined: November 25th, 2011, 11:35 am

October 15th, 2017, 1:07 pm #5

two reasons.

Firstly, under the right conditions, it also can corrode. The other issue is that it is a dark greyish metal which is not in everyone's favourite taste

Secondly, Titanium is prone to galling far more than stainless steel and therefore the Rolex company do not want to increase their liability of having this problem.

Let me add that 904L was designed to hold sulphiric acid and although good against chloride attacks, it is still not noble enough to compare against Gold and Platinum where pitting and corrosion is concerned!!! If it were, whoeever metallurgist was responsible would be very rich !!!!

If the Rolex company would allow me to create my own case at no extra cost, I would ask for one to be made from an alloy known as 6Mo which is high in Molybdenum. If they allowed me to go even further, I would choose a Platinum mid case and a white gold case back, covering both corrosion and galling!!! So here I am, I justI keep dreaming !!!!
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