Rolex

Dear friends I send a greeting and would you know when year they started to use the rolex steel 904L .

I appreciate your comments.

Best Regards

Rene Chimal 

Mid '80s. Notable Sub 168000 used the 904 steel, same case as the 16610, but guts of 16800.

May you explain the advantages of the 904 L compared to the previous SS ( 316? )

Thanks in advance!

Best,

Nicolas

More resistant to corrosion than 316L, but that is on the Rolex website.

Same as far as scratch resistance.

Funny thing is the nickel content is higher in 904L than 316L.

Rolex simply could have stayed with 316L, but

just wanted to show they could work 904L, which doesn't machine easily,

into a watch case.

Is better at resisting pitting and crevice corrosion. (ie, corrosion that occurs in the gaps and slots around gaskets where the lack of oxygen means that the protective oxidised layer cannot form).

904L has a higher PRE (Pitting Resistance) number than 316L, due to - as Rick2 states - higher proportions of nickel. etc.

Having seen lots of old dive watches with pitting and corrosion around the case-back o-ring and landing, I think the 906L is a move in the right direction. Whether it makes a REAL difference, is difficult to determine.

As for machining, it is more difficult than 316L, but not that difficult. Titanium is much more of a challenge. And who made the first Titinium Dive watch??

This message has been edited by BDLJ on 2009-07-27 20:10:31

Panerai with the Egiziano ( a very few models ) in the mid 50ies?

Best,

Nicolas

I thought the Egiziano was in Stainless steel (the replicas are titanium, though?).

Titanium was pretty rare and exotic stuff in the 50's. It was mainly confined to aerospace activities. Makes you wonder where they got their hands on some...?

Of the production watches I'm aware of, I think Seiko did one in the 70's or was that ceramic....must do some searching.

AFAIK, some protos of the Egiziano were made in Aluminium...Not titanium...

Best,

Nicolas

I think DuPont was the first company to refine the metal in commercial quantities in the late 1940s. They used a process developed in Luxembourg in the 30s, Titanium Chloride reacts with Calcium to form Calcium Chloride and pure Ti. 
A

Hi Aaron,

I think the first to produce commercial (well, semi-commercial, it was mainly for military/strategic purposes) was TIMET in 1950/1.

They refined and commercialised the Kroll process that you described above. Interestingly, by '53 production was only 2000 tons....miniscule.

 

The Panerai Radiomir Egiziano was made for the Egiziano (Egyptian) Navy in 1956. Reference # was GPF 2/56, 60 mm Stainless Steel dive watch. Some 50 were supposedly made.

Seiko claims in 1975 to have made the first titanium case dive watch. Reference # 6159-022. 600 m rated.

Seiko 6159-701x? That's a dream of mine. Hard to find one without a dinged up bezel. I couldn't remember whether it was the first titanium case or the first ceramic shroud. It's both. The 6159 is a 36,600 beat movement - fundamentally a GS movement with less decoration. Awesome and often overlooked watch.

No, the ref. is 6159-022, and as SJX posted on this thread, this watch had a ceramic shell, over TITANIUM! Watch also employed a rubber strap,

especially designed to reduce constriction on the wet suit. No HEV for saturation dives. A special rubber gasket solved that.

Flip over the original shrouded diver and what is stamped on the monocoque caseback?

6159 - 7010 (or 7019 depending on market).

I know about the claims of Seiko for titanium and ceramics (and tend to believe them). The intent of the discussion was to see whether there were any earlier watches that we may have missed. Like most "firsts" it can get murky.

Very interesting to know it, finally!

Best,

Nicolas This message has been edited by amanico on 2009-07-28 23:04:53

since the "tuna can" diver had a titanium inner case with a ceramic 'shroud'. IWC later made the first watch with titanium case AND bracelet.

- SJX

Is it true that the higher nickel content in 904 makes it more allergy-prone?

Well, I'm not sure.

According to my Materials Handbook, 904L is 23-28% Nickel, while 316L is 10-14%. So twice the amount of Nickel. So I guess if the 316L gives you allergy troubles, the 904L is going to be worse.

This poses another question: what are the bracelets made from?

I don't see why Rolex will use another solution ofr their bracelets....

But I'm curious to know...

Best,

Nicolas

Hi all,

Just wanted to share something very interesting with you.
A french forum member, called Jean-Michel, made a very interesting test.
He decided to evaluate how hard is the 904L compared to 316L in some different acids...
This is exactly what he did:

Protocol of test: ageing and accelerated corrosion of various alloys: extract of the various tests carried out

30 minutes 120°C 100% of moisture at saline saturation
24 hours in the acid sulfochromic
24 hours in the acid chloridric
48 hours in ammonium bifluoride at saturation

Result….



Credits: Jean-Michel

Thanks for viewing.

904 nickel content poses a problem for those who have skin sensitivity so only the parts that are not touching the skin were made in 904.  I've done analysis on two newer models and both have 316 for the bracelet. 

Thanks for that info, Scott.

Does that mean the caseback is also 316L? So much for extra corrosion-resistance in this key area!

he tells me the change to 904L should have been around 1988.  The entire watch is now suppose to be 904L, this includes the bracelet.  But, I spoke with him about my findings and he agrees there was a good period of lead-in where 316 was still being used.  My tests back this up.  I will soon be testing other newer Rolex models and should find 904 to be the only material used.  Even though 904 has double the content of nickel, it's chromium content is suppose to help in shielding the nickel.  How accurate that comment is, I don't yet know.  Anyway, this comes from the horses mouth!  The 904 was chosen because of the pitting that occurs over time in 316 which makes it more challenging when servicing the watch.

Thanks

Scott

if the WG Rolex is Rhodium plated for the white finish, or is the 25% other alloy in Rolex's white gold platinum????