904L Stainless Steel Question

[Guest HaloArchive]

What year was 904L stainless invented and what year was it first used in Rolex?

Thanks!

H

[ubiquitous]

I seem to recall it was introduced in the mid 80's or roughly there about. I don't remember what specific serial year ref it was, however.

[Guest HaloArchive]

I cant find it on the net and, this guy I know who works for an AD just wants to say im wrong. He told me that 904L has no nickel in it >.> and says that it was only introduced in the 2000's o.O

So, if anyone knows, that would be great!

[ubiquitous]

I think the transition took place with the 168000; say around 1986/7? I think those were brought out in the 9.5M serial range. I know the 16800 was still using 316...

[Archimede]

hi

[ubiquitous]

9.3M... So I was off by a couple hundred thousand in the serial range...

[Guest HaloArchive]

So, the 1680 was part of a transitional series and part transitional model changing from 316 to 904L?

[Sweattdogg]

Fairly sure it still has nickel in it.

[ubiquitous]

So, the 1680 was part of a transitional series and part transitional model changing from 316 to 904L?

1680 and 16800 was 316. The 168000 was 904L.

[Guest HaloArchive]

Excellent, so, what I said was right then to that guy. And, All SS contains nickel. I couldnt believe he said that xD

[ubiquitous]

That's correct- 316 and 904 both have nickel content. 904L just has more of it...

[Fidestro]

Forget about the watch, check out the [censored] on Archimede's avatar!

On Topic: I was talking with an engineer at work about the cost difference between 316 and 904 and he estimates that on a watch and bracelet Rolex MAY spend $100 total in the steel cost, depending on volume, how they machine it, etc. And yes, it has Nickel in it.

I should state those numbers are based on two guys standing around talking, nothing scientific.

[docblackrock]

Fairly sure it still has nickel in it.

That's correct- 316 and 904 both have nickel content. 904L just has more of it...

I'll happily back this up by saying it DEFINITELY still has nickel in it, lots of it in fact - contrary to belief it wasn't chosen by Rolex for any hypoallergenic reasons, but for its 'whiter' finish and slightly increased durability.

904L Stainless Steel

C 0.02%

Cr 19.0-23.0%

Cu 1.0-2.0%

Mn 2.0%

Mo 4.0-5.0%

Ni 23.0-28.0%

P 0.045

S 0.035

Si 1

DESCRIPTION

904L is a high-alloy austenitic stainless steel with low carbon content. The grade is intended for use under severe corrosive conditions. It has been application proved over many years and was originally developed to resist corrosion in dilute sulfuric acid. It is standardized and approved for pressure vessel use in several countries. Structurally, 904L is fully austenitic and is less sensitive to precipitation ferrite and sigma phases than conventional austenitic grades with high molybdenum content. Characteristically, due to the combination of relatively high contents of chromium, nickel, molybdenum and copper 904L has good resistance to general corrosion, particularly in sulfuric and phosphoric conditions.

DESIGN FEATURES

Good resistance to pitting and crevice corrosion.

Very good resistance to stress corrosion cracking.

Good resistance to intergranular corrosion.

Good formability and weldability.

Maximum service temperatures of

450 deg.C. (824 deg.F).

TYPICAL APPLICATIONS

Production and transport of sulfuric acid

Metal pickling in sulfuric acid

Production and concentration of phosphoric acid

Use in seawater, brackish water, condensers, heat exchangers and pipe work in general

Paper and allied industries

Gas washing

Chemical and pharmaceutical industries

http://www.allstainlessltd.co.uk/info/904.html

I'll not copy it here, but if you want to compare composition with 316, then here it is also.... note the Ni content is at around 10-15%, almost half of that in 904L.

http://www.allstainlessltd.co.uk/info/316.html

[Guest HaloArchive]

Very interesting stuff

Thanks everyone!

+Rep

[fakemaster]

1988