Steel threads

[jhe888]

There have been a few discussions about stainless steels here over the last few days. This is a far more complicated topic than these discussions even hint at. I only know just enough about steel to know that I don't know much about it.

Hardness, toughness, stain resistance, and workability are qualities steel can have, and which various alloys have in differing degrees. There is no one best steel as it depends on the application, and you would even have disagreements about which steel is better in a particular application, as one alloy may be superior in one respect and inferior to another in a different quality. The stainless steels that make good watch cases would make terrible knives, and a steel that makes a good filet knife would not be very good for a chopping knife, for example.

There have been a lot of misconceptions shared in some of these threads, and misuse of terms. Some people seem to buy the marketing department's hype without really knowing what is going on.

Here is some actual information:

904L is very stain resistant and resistant to acids. Apparently it polishes up very nicely, welds well, and is workable. It is tough, which isn't the same as hardness. http://www.azom.com/article.aspx?ArticleID=1022

316L is similar, although probably not as resistant to acids. It also welds well, and is tough. We all have watches made from it, so we know it polishes nicely. http://www.azom.com/article.aspx?ArticleID=2382

Both make a fine watch which will not corrode under normal use, even if that use includes exposure to salt water. I bet Rolex could switch back to 316, and no end user of watches could tell the difference. 904 may have some advantages, but they seem slight in this application.

Here are some general pieces about stainless in general, which, at least, give a hint as to how complex the subject is.

http://www.asminternational.org/docu..._Chapter_1.pdf

http://www.azom.com/article.aspx?ArticleID=470

Here is the definition of terms that describe metals, so we can use them correctly:

http://www.tpub.com/air/1-18.htm

[fluxcore]

The difference between these two steels are negligible in everyday situations.

Only in extreme exposure to temp or acids will the 904L really start to shine. And in that case, what's on your wrist will be the least of your concerns.

[jjnd08]

Nice summary, John!

[tkerrmd]

good stuff John, thanks!

[GradyPhilpott]

[gontomt]

You know something (e.g. metallurgy) is "not so simple" if top-echelon universities offer PhD degrees on the subject, and practitioners of the discipline are so well remunerated. Good post, OP.

[Tools]

The older 316 cases used to routinely corrode at the case back gasket/seal junction, likely from the body acids and oils that seep in there, causing waterproof test failure. The more resistant 904 doesn't seem to show pitting and corrosion to the same extent.

But even if it's resistance is minimal it really doesn't matter, Rolex has chosen to use this more costly steel. We acknowledge that they want to set themselves apart with 904L the same as others do with Titanium or ceramics; it's the nature of a business to market to these things..

Just accept it and enjoy it..

[Dirt]

Originally Posted by Tools

The older 316 cases used to routinely corrode at the case back gasket/seal junction, likely from the body acids and oils that seep in there, causing waterproof test failure. The more resistant 904 doesn't seem to show pitting and corrosion to the same extent.

But even if it's resistance is minimal it really doesn't matter, Rolex has chosen to use this more costly steel. We acknowledge that they want to set themselves apart with 904L the same as others do with Titanium or ceramics; it's the nature of a business to market to these things..

Just accept it and enjoy it..

Absolutely correct

Some people have more acidic perspiration than others.
Add in exfoliated skin particles to retain the acids which are constantly replenished that form a corrosive compound, along with elevated temps and ongoing moisture and it's virtually a pickling paste that never sleeps and is constantly eating away at the mid case seal surface.

Anyone who has collected enough vintage Rolex Watches, will attest to the reality of the long term intergranular corrosion problem of the mid case.
The resultant pitting is quite profound.

If Rolex chooses to mitigate the issue with the use of 904 SS, them I'm personally not going to complain.
Thankfully, since the introduction of the use of 904 SS there have been no corrosion issues that I know of.

[Sublover2166]

Is there any difference in the "brightness" or hue between the two? My Hulk Sub seems to really "pop" on my wrist and I don't remember an all stainless watch being so "bright". I had a 16610 Sub probably 20 years ago and don't remember it appearing like my Hulk. Maybe just a bad middle aged memory failing me!

[Dirt]

Originally Posted by Sublover2166

Is there any difference in the "brightness" or hue between the two? My Hulk Sub seems to really "pop" on my wrist and I don't remember an all stainless watch being so "bright". I had a 16610 Sub probably 20 years ago and don't remember it appearing like my Hulk. Maybe just a bad middle aged memory failing me!

Apparently there is a slight difference between them, but I've never bothered to take much notice.
They all still look great regardless.

Only a side by side comparison will reveal any differences.
When the watch is worn on the wrist, the issue is irrelevant and is eclipsed by the ownership experience anyway

[treblarefils]

Maybe it is in my head but my subc really does pop it could be Rolex finishing technique or the steel but it is amazing. None of my other watches steel comes even close and fit and finish is perfect as expected in this price range. From another person's perspective it would seem as if they should be able to tell they are obviously looking at something special. Even from new cleaning my watch with the wristclean vereat spray seemed to brighten the watch more than it already was.

[watchwatcher]

Very educational thread.

[breitlings]

with all due respect there are real life examples of watches sent to rsc that had corroded case threading. they can be found with simple google searches. 904l should not have that issue. it seems that a lot of people are believing there is no difference in the steels which is a misconception.

[visualplane]

Thank you for this thread

[ernie2]

i don't know if it is just me. I think the polishing on the 904L steel is easily scratched than other steel ( 304 / 316.etc). I have a 42mm Polar explorer 2 and a SD4K. I don't recall anything remotely impacted with the watches, the polished left sides ( the 9o'clock side) have many many hairline scratches. May be they were caused by putting down the watch crown up at the table sometimes. Every now and then, I will see a new scratch and nothing has been in contact with the watch except my skin.

I have other steel watches such as Tag Heuer and Bell & Ross and I wore and placed everyone of them in the same manner as my Rolexes. None of the other watches got the amount of scratches as seen on the Rolexes.

Wonder if anyone got the same observations.