which is more durable Titanium or Stainless steel LED lights...

[Illum]

durable or not, neither is ideal for thermal dissipation:tired:

 

[StarHalo]

 

[MKLight]

StarHalo - very interesting, especially with the HAIII info! :twothumbs!

 

[MrGman]

That's a good combination of data Starhalo.

While it is certainly very common to get Aluminum flashlight hosts anodized. I don't think its common to get Titanium hosts treated and from what I have read here on CPF in general, certainly doesn't sound like it on the commercially available units. So even though the properly treated Titanium surface is very hard and abrasion resistant, won't mean much if its not available on the product some one is buying hoping for that very feature assuming its inherent in the product and yet not there.

 

[saabgoblin]

The assumption that Ti lights will have thin wall thicknesses because of the high cost of Ti, and will therefore be likely to be dentable/deformable, is questionable.

This previous thread went into the pros and cons of Ti for flashlights quite a bit:https://www.candlepowerforums.com/threads/140414&highlight=titanium+electrical

Just for clarity, I am not only assuming that only Ti Lights may be thinner walled but SS as well, all depends on build quality and cost effectiveness dictated by either the company and or consumer.

Personally, I have quite a few Brass lights and I find that I like the battle scars, dings and dents left by dropping the light. What may also be a critical factor is the shock resistance of the electronics.

Great information Star Halo thanks for pooling and linking the data.

 

[fnj]

That being said, some grades of stainless are much more stainless than others. 316 stainless for example contains a high percentage of nickel and chromium, and is extremely difficult to rust, and will stand up fine to seawater.

Agreed that grades differ, and 316 is one of the best, but 316 stainless immersed for lengthy cycles in and out of ocean water will rust. Ti-6Al-4V with the same use undergoes markedly less corrosion in that environment; however, even it will have the original shine gone. In the oceanographic industry I've seen both after real world exposure.

 

[adnj]

All iron will rust -- the chrome content of stainless just makes it rust more slowly.

There are some nitrogen processed steels taht will not rust at all. I have a $300 Spyderco I bought for use on an ocean kayak. It never rusts. Never.

 

[MKLight]

Agreed that grades differ, and 316 is one of the best, but 316 stainless immersed for lengthy cycles in and out of ocean water will rust. Ti-6Al-4V with the same use undergoes markedly less corrosion in that environment; however, even it will have the original shine gone. In the oceanographic industry I've seen both after real world exposure.

Very cool. Out of curiousity, what are the visual affects of both the 316 and Ti-6al-4v? Also, would the metal really bean an issue in this case or would orings be more susciptible to failure? Very interesting. :twothumbs

 

[McGizmo]

Unless the light is made from thin wall tubing, the wall thickness of the light will be a function of design and not cost. If it starts as a solid bar, whether the metal is left as part of the light or chips in the bin, it has already been paid for. One might argue that a thin wall could be more expensive in terms of machine time.

As others have stated, the actual alloy of the metal can be a significant factor as well as any heat treating for alteration of physical properties.

Durability also needs to be better defined. Durable in a corrosive environment or durable in an abrasive environment or durable in a knock about environment? Durability in terms of function and integrity or durability in terms of cosmetic considerations?

If you are looking at two lights that are the same exact construction then you need to consider the actual alloys of metal being used, any heat treating or other treating effecting the physical properties and then consider the nature of exposure and stress the lights will be subjected to. At that point, you might find that you would consider one metal more preferable than the other, in terms of durability.

If thermal dissipation is a problem then stick with diamond and accept no substitutes! :nana:

 

[fnj]

Very cool. Out of curiousity, what are the visual affects of both the 316 and Ti-6al-4v? Also, would the metal really bean an issue in this case or would orings be more susciptible to failure? Very interesting. :twothumbs

The stainless is rusty and pitted, yuck. The titanium just appears a bit discolored and degraded, with some surface corrosion, but mostly it has just lost its sheen. Some wire brushing and steel wool and it looks beautiful and brand new again.

The O rings are basically not affected. They look like they could be re-used, but they are so cheap, and the bottle itself and the stuff inside and the mission are all so expensive that you slap on fresh O rings at reassembly.

Mill finished stainless steel looks like crap. It has a dull appearance and will develop tiny spots of corrosion which will spread. This arises from traces of free iron on the surface which lead to galvanic action. It has to be polished and passivated. The passivation (basically pickling in acid) removes free iron surface contamination on the stainless steel and allows a uniform optimal chromium oxide film to develop. This self-repairing "film" is incredibly thin, transparent (believe it or not), and is the basis for the the continued clean, corrosion-free, beautiful mirror-like appearance of finished stainless steel.

Think about this phenomenon. Chromium actually oxidises more readily than iron! That is the basis for the protective layer atop stainless steel. I remember how disillusioned I was to learn this.

If you want to see stainless corrode, just get sloppy with your dishwashing and leave stainless cutlery in tap water for an extended period of time. It's not the chlorine, because well water will do just fine. They will start to get fine pitting; this will not go away, and will only get worse over time. Granted, this is not ocean grade stainless, but the principle is the same; only the rate of corrosion is different.

I will also never forget the appearance of one big heavy piece of brass that had been left on the factory roof for years. It looked like heck and was covered to a significant depth by something that looked and felt exactly like common rust.

 

[HitecDrftr]

Heavier bezel will make no difference whatsoever. A feather will fall at the same speed as a hammer in a vacuum. It has been tried on the moon.

Man, how did they get a hammer inside a vacuum? Mine has nowhere near that kind of suction... :shakehead

 

[Cheapskate]

Its not an assumption that some people have already complained that they have "dented" their Titanium flashlights by dropping them...
As to scratch resistance and corrosion resistance. hard anodize level III certainly beats SS or Titanium hands down. Cerakote is even better and still cheaper than equivalent sized and featured flashlights of Titanium.

But not all Ti lights have thin walls. It is not a generic trait common to all Ti lights.

I have a Ti flashlight and the main barrel wall thickness is 3.1mm - and that's 6Al-4V alloy, not CP grade. No way would you be able to dent or deform it by dropping it.

So a general statement that Ti flashlights will always be made with thin walls due to the cost of the material is untrue.

Corrosion resistance that relies on a coating is often a failure waiting to happen.

SS and Ti lights can both be tough as nails, it's just the Ti ones can be made a little lighter.

 

[MrGman]

But not all Ti lights have thin walls. It is not a generic trait common to all Ti lights.

I have a Ti flashlight and the main barrel wall thickness is 3.1mm - and that's 6Al-4V alloy, not CP grade. No way would you be able to dent or deform it by dropping it.

So a general statement that Ti flashlights will always be made with thin walls due to the cost of the material is untrue.

Corrosion resistance that relies on a coating is often a failure waiting to happen.

SS and Ti lights can both be tough as nails, it's just the Ti ones can be made a little lighter.

I agree with most of these statements. I don't believe HA III coatings on Aluminum is a "failure waiting to happen" Its pretty well know reliable commodity.

My comment would be that the purchaser of a flashlight isn't going to know how thick the walls are in most cases from the marketing information provided by the sellers or manufacturers. Some are made more rugged than others but how does the general consumer know. Same thing with the Stainless steel. they aren't publishing that I have seen that a certain SS flashlight host is made with XXX series stainless where we can look up its properties. SS varies quite considerably for a wide variety of applications. Groups that do good evaluations of the flashlights that we get to do a review on may show you the wall thickness but I have yet to read a single one telling you a metallurgical analysis that the Titanium alloy was such and such or that the SS alloy was such and such.

So yes you can buy a flashlight with relatively thick Titanium walls and it will hold up much better than the one some one else bought that dented on one drop. My point is how was that guy supposed to know not to buy that flashlight before he plunked his money down? If I buy a $25 flashlight host and it gets banged up I am not going to get heartburn over it. If I buy a $350 flashlight system and it gets banged up when I was expecting it to be a lot more robust I am going to get ticked off about it. Or if I was expecting that same $350 flashlight's shell to be highly resistant to scratches and find that it wasn't the hard way. What then.

If these vendors are going to be marketing expensive flashlights with Titanium shells or hosts that supposedly make the flashlight more valuable in that it should be stronger and more abrasion resistant than they should be telling us what the wall thicknesses are and the alloy and its relative hardness and abrasion resistance scales instead of just showing a shiny "Ti" flashlight.

Real Flashoholics do not live by shelf queens alone.

 

[Cheapskate]

Well one way is by the weight.

When Jetbeam give the weight of the aluminium III M as 118g and the Ti version as 190g, it does give a clue that there is good amount of material there and they did mention the alloy - 'Fabriquée en alliage Titane TC4'.

Then of course there are the inevitable tear down photos from early adopters

But I would agree with you that, 'features' should be thoroughly categorized and specified.

What I meant about coatings was that where their main purpose was corrosion protection, any injury to the coating will likely soon lead to corrosive failure. Ding something made of Ti that is used in a corrosive environment and all you have is a ding; do the same to coated Al and it is the beginning of the end.

 

[olrac]

Well one way is by the weight.

When Jetbeam give the weight of the aluminium III M as 118g and the Ti version as 190g, it does give a clue that there is good amount of material there and they did mention the alloy - 'Fabriquée en alliage Titane TC4'.

Weight is not an indicator in itself. 1" dia. x 1" long rounds of 6061 alum., Titanium and 300 series S.S weigh .0771, .1280, .2294 lbs. respectively though they are the same amount (volume) of metal, so with the jetbeam example they both are around the same equivalent amount of metal but the TI is denser

 

[MKLight]

The stainless is rusty and pitted, yuck. The titanium just appears a bit discolored and degraded, with some surface corrosion, but mostly it has just lost its sheen. Some wire brushing and steel wool and it looks beautiful and brand new again.

The O rings are basically not affected. They look like they could be re-used, but they are so cheap, and the bottle itself and the stuff inside and the mission are all so expensive that you slap on fresh O rings at reassembly.

Mill finished stainless steel looks like crap. It has a dull appearance and will develop tiny spots of corrosion which will spread. This arises from traces of free iron on the surface which lead to galvanic action. It has to be polished and passivated. The passivation (basically pickling in acid) removes free iron surface contamination on the stainless steel and allows a uniform optimal chromium oxide film to develop. This self-repairing "film" is incredibly thin, transparent (believe it or not), and is the basis for the the continued clean, corrosion-free, beautiful mirror-like appearance of finished stainless steel.

Think about this phenomenon. Chromium actually oxidises more readily than iron! That is the basis for the protective layer atop stainless steel. I remember how disillusioned I was to learn this.

If you want to see stainless corrode, just get sloppy with your dishwashing and leave stainless cutlery in tap water for an extended period of time. It's not the chlorine, because well water will do just fine. They will start to get fine pitting; this will not go away, and will only get worse over time. Granted, this is not ocean grade stainless, but the principle is the same; only the rate of corrosion is different.

I will also never forget the appearance of one big heavy piece of brass that had been left on the factory roof for years. It looked like heck and was covered to a significant depth by something that looked and felt exactly like common rust.

Thank you, fnj. You really painted an interesting picture :grin:. I really appreciate that.

Thanks again,
MK

 

[MrGman]

Think about this phenomenon. Chromium actually oxidises more readily than iron! That is the basis for the protective layer atop stainless steel. I remember how disillusioned I was to learn this.

Not sure what you mean by this as in in it corrodes worse or that it reaches an oxidation state more readily than Iron does. Chromium is used because it oxidizes and creates a thin barrier film in which oxygen will not continue to penetrate to create further and deeper corrosion whereas as Iron will corrode and Iron Oxide will not stop the further penetration of more oxygen and so the "rust" just keeps going deeper and deeper.

"Chromium metal left standing in air is passivated by oxygen, forming a thin protective oxide surface layer. This layer is a spinel structure only a few atoms thick. It is very dense, and prevents the diffusion of oxygen into the underlying material. This is in contrast to iron or plain carbon steels, where the oxygen migrates into the underlying material and causes rusting.[17] The passivation can be increased by short contact with oxidizing acids like nitric acid. Passivated chromium is stable against acids. The opposite effect can be achieved by treatment with a strong reducing reactant that destroys the protective oxide layer on the metal. Chromium metal treated in this way readily dissolves in weak acids.[15]"

So its a good thing that Chromium oxidizes as it does and that is why its used as it is. Not sure from the way you worded your statement but you make it sound like it won't help prevent oxidation and corrosion of the stainless steel for the long term, which it most certainly does. Of course not all stainless steels are the same. Cheap SS cutlery is not a good example of the best SS alloys out there.

Titanium oxides and forms a thin barrier layer that prevents further oxidation as well the same as for Chromium. I believe it makes titanium dioxide. So if your disappointed in Chromium for this reason, you should be no less disappointed in Titanium for the same reason. The Chromium actually doesn't loose its shine with the oxidation layer whereas the Titanium does as you observed.

Now whether or not SS flashlights being marketed are using the best SS alloys available for the prevention of corrosion as well as hardness and overall durability or just for making a buck on something different than the common Aluminum alloy hosts, that is a different question.

 

[Dan FO]

I will almost bet these SS flashlights are made of a 300 series stainless. 316L is used in most high end stainless watches except for Rolex which uses 904L. With all of the salt and acids in your skin how often do you see a good stainless watch rust? There are several instances where stainless watches have been recovered weeks and even years later that worked and showed no rust. If I were building the light I would probably use 317L.

 

[combinatorix]

Agreed that grades differ, and 316 is one of the best, but 316 stainless immersed for lengthy cycles in and out of ocean water will rust. Ti-6Al-4V with the same use undergoes markedly less corrosion in that environment; however, even it will have the original shine gone. In the oceanographic industry I've seen both after real world exposure.

I think all I'm trying to say is 316 stainless used for a flashlight won't rust noticeably even if exposed to or used in seawater. Yes, extended periods (days+) in warm seawater will cause corrosion, but unless it's a dive light I don't think it's really a factor.

316 is also still just a very common stainless alloy (and much cheaper than a high grade of Ti). I know spyderco makes knives in what they call "H1" steel which is extremely corrosion resistant and can hold a pretty decent edge as well. I don't really see flashlights turning to any of those expensive grades of SS, but you don't see them using the higher grades of Ti often either..

 

[StarHalo]

Would you seafaring folk work with a Surefire G-2/Nitrolon flashlight?

I intend on adding Nitrolon to the materials chart above, but the specific blend Surefire uses isn't listed anywhere; its tensile strength can vary widely depending on the formula, so I will eventually e-mail them for details. Evidence suggests it has a hardness of 2 Mohs, but it supposedly has the ability to absorb small quantities of water which can weaken it.

I will almost bet these SS flashlights are made of a 300 series stainless.

The numbers in my chart for SS average both 300- and 400-series SS, as I am also betting many flashlights are 300-series.