# 316l or 416 Stainless?



## jbenham1 (Sep 12, 2012)

What are your thoughts on 316l Stainless vs. 416? Are there any other grades that are interesting and worth a look at for a watch casing?

I know there are a lot of threads about 316l vs. 904l etc. 416 doesn't come up a lot, maybe because it pits more easily?

Info about 316l and 416 (taken from a site, not proven to be correct):

Read the following properties which is taken on 1 to 10 scale :

SS316:

FORMABILITY:8

Machinability:5

Weldability:8

SS416 :

FORMABILITY:1

Machinability:10

Weldability:1

* SS 416 is Good For:

- Excellent machinability - best of the common stainless steels - readily used for high
productivity machining.
- Useful scaling resistance to about 700 Deg C.
- Can be hardened and tempered to give high hardness or strength, so useful for shaft
applications.

Not Good For:
- Poor resistance to general corrosion, due to the Sulphur addition.
- Very poor resistance to Chloride pitting and crevice corrosion - not suitable for any
marine applications at any temperature.
- Low ductility - cannot be bent around a tight radius, or heavily drawn.
- Poor weldability - not regarded as weldable.

*316
Good For:
- Good resistance to a wide range of chemicals - generally somewhat better than 304.
- Useful resistance to Chlorides, especially if cold - safe sea water temperature 22 Deg C.
- Higher resistance to pitting and crevice corrosion than 304 - PREN = 24.
- Excellent formability - readily deep drawn, bent and forged hot or cold.
- Available in an Improved Machinability "Ugima" form.
- Excellent Weldability.
- Useful high temperature strength to 870 Deg C - higher hot strength than 304.
Not Good For:
- Poor resistance to stress corrosion cracking - susceptible above 60 Deg C in even low
Chloride environments. No better than 304 - use 2205 instead.
- Not suitable for exposure to hot concentrated nitric acid - 304 is better.
- Reduced scaling resistance in some environments above about 500oC, due to
Molybdenum.
- Low strength, particularly proof stress, limits structural use.

What other grades are interesting to look at?

What are your thoughts?

Hardwearing, clean finish are important. watch not designed for sea use etc. so extreme corrosion resistance not important.


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## xzqt (Jan 26, 2013)

Base on the above specification, the answer is already there for watch case usage :

 SS 416 
Not Good For:
- Poor resistance to general corrosion, due to the Sulphur addition.
- Very poor resistance to Chloride pitting and crevice corrosion - not suitable for any
marine applications at any temperature.....................

*316
Good For:
- Good resistance to a wide range of chemicals - generally somewhat better than 304.
- Useful resistance to Chlorides, especially if cold - safe sea water temperature 22 Deg C.


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## jbenham1 (Sep 12, 2012)

I know the 316l is the more obvious choice, it was more an introduction to an open dialogue about other grades and their quirks, it would be nice to find a grade I haven't heard of or considered, especially because marine use etc. isn't what the watch will be used for. 

Cheers for your reply.


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## pithy (Aug 22, 2010)

jbenham1 said:


> I know the 316l is the more obvious choice, it was more an introduction to an open dialogue about other grades and their quirks, it would be nice to find a grade I haven't heard of or considered, especially because marine use etc. isn't what the watch will be used for. Cheers for your reply.


unobtanium 2217


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## jbenham1 (Sep 12, 2012)

pithy said:


> unobtanium 2217


I can't seem to find that pithy, is it a kind of stainless? Is it waterproof?

----

Something that actually is unobtanium is 0.4mm glass and how to cut it!!


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## pithy (Aug 22, 2010)

Myself - I'd use sterling silver or fine (one of those big commerative coins) or some hypoallergenic bronze - but that's just me. Anything other than tungsten carbide is OK though. [I'd like to have a Benham #1 in blued gunmetal. What do you think?]

All the ss can be brushed but some of it is a bear to bring to high polish.


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## xzqt (Jan 26, 2013)

Ohh, for discussion purpose.

Than may be :
bronze
Sterling silver
904 stainless steel, a low carbon, high alloy austenitic _stainless_ steel. It has excellent formability, weldability and toughness. Resistance to warm sea water and other high chloride environments.
Tungsten
Titanium (my favourite for diver watch !)
Even 14K gold !


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