Poll: Can You Tell Which Is Which?

Which One Is Stainless Steel?

  • Top

    Votes: 63 38.4%

  • Bottom

    Votes: 64 39.0%

  • Unsure

    Votes: 37 22.6%
  • Total voters
    164
  • Poll closed .
As I said in the other thread, stainless can be told apart from carbon steel in some circumstances. This was one of them. Namely, when side by side with a known carbon steel, it often looks slightly more yellow. Not in every case, but in this one I was fairly positive, and was right. Now many of you probably didn't even notice this, but having long years of experience with machining steel I saw it right away. Now that you know, take a closer look at the photo and see if the bottom blade doesn't have a slightly yellow tint compared to the top one, which looks more purely silver-white.

It is likely this is due to slight oxidation of remaining few free iron particles on the surface. I'm guessing that Mora doesn't passivate their blades. In addition, if they grind the blades in the same factory as their carbon steel blades without keeping them very well separated, even the dust in the air can "contaminate" the surface of the stainless blades with free iron particles. Another no-no is using the same abrasives on both carbon and stainless steel.

If these blades were freshly polished, they would likely be indistinguishable. Now of course this yellowing doesn't tell you immediately that the blade is stainless, but the question was can you tell carbon steel from stainless steel when they are side by side. In this case, yep, because we KNEW one was carbon steel and one was stainless. In any case, if you suspect a blade is stainless, obviously the eye test is NOT definitive by any means. I don't think that anyone would claim otherwise.
 
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Mecha said:
Yes, they can all look different from each other even just from heat treatment alone. I’m not looking at the flat color, but the irridescence. I’m asserting the radical notion that a specific element looks a certain specific way and that one can learn to recognize its visual effect when heavily blended into a very common alloy. Chromium isn’t some magic element that becomes invisible as soon as it touches iron. If it was extremely common to use steel that had 15% tungsten in it or what have you, it would be possible to learn to recognize that too. Stainless steel is just “hard mode.” Copper would be easy mode, for example.

There is no evidence beyond the commonplace anecdotal to “prove” either claim. One is just normally assumed and accepted. I’m sorry if others can’t see it, but that doesn’t mean it’s impossible.

There are many people who can reliably see the difference between and pretty accurately identify 24k gold, 18k gold, 14k, rose gold, white gold, etc, purely due to what is alloyed into the gold. Just because they can see it doesn’t mean they don't test the gold to make sure, or that jewelers don’t mark their pieces. Steel is no different, just much more difficult due to all the silvery alloying elements, usually in small quantity...except chromium in stainless: large quantity, very common, not invisible.
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I'll check again tomorrow and look for the irredecence. I love looking at them anyway!:)
 
OK - Now do it again. :thumbsup: At the risk of coming across as a smaat arse, I'm pretty certain that I identified the bottom because of a slight color shift that "told me" that one. Bet I can't see it twice in a row. Could have been the amount of shadow or reflection of the photographer combined with a 50:50 stupid lucky guess - but I saw the color shift o_O, really. Would be happy to try again though. :rolleyes:

Anybody? ;)

Ray
 
ucfgrad93 said:
So, how am I supposed to know which it is? I don't know anything about the company, and the knives aren't labeled. Is it the blue handle or red handle?
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The knives are the Mora 511 (red) and 546 (blue), which have their handles color-coded to indicate the steel type. My apologies if it wasn't obvious, but I believed it to be common knowledge since Mora themselves is a highly popular company and these are sort of their staple models. They've been doing the ol' red (carbon)/blue (stainless) color coding for decades. :)
 
RayseM said:
OK - Now do it again. :thumbsup: At the risk of coming across as a smaat arse, I'm pretty certain that I identified the bottom because of a slight color shift that "told me" that one. Bet I can't see it twice in a row. Could have been the amount of shadow or reflection of the photographer combined with a 50:50 stupid lucky guess - but I saw the color shift o_O, really. Would be happy to try again though. :rolleyes:

Anybody? ;)

Ray
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You saw the slight yellow shift. This is very visible. I have had old stainless parts in the shop many times that I had to remachine or polish only a small section of, and the color difference is immediately noticeable as soon as the work is polished. The older section has the yellowish tint and the fresh polished surface turns silver-white again. Again, this is not always the case - if the stainless is freshly polished or passivated and kept from exposure to free iron, it will be visually indistinguishable from carbon steel. The thing is, it's pretty difficult to keep stainless free from iron. Even a tiny amount in the air as dust can do the trick.
 
FortyTwoBlades said:
The knives are the Mora 511 (red) and 546 (blue), which have their handles color-coded to indicate the steel type. My apologies if it wasn't obvious, but I believed it to be common knowledge since Mora themselves is a highly popular company and these are sort of their staple models. They've been doing the ol' red (carbon)/blue (stainless) color coding for decades. :)
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I'm relatively new to knives, and had never heard of Mora before your initial post. I like how they do that. Thanks for the information.
 
It just looked like more of the stainless I have seen and worked with in boatyards, fittings as well as fasteners. Still, so much of this test was subject to many variables, not the least being the type of device one is using to look at the photo.

Ray
 
As previously noted, this was all purely anecdotal/casual rather than scientific. But it does at least provide some small evidence that for these conditions (looking at a static photo of the two knives, taken in natural overcast lighting with a DSLR camera and viewed on a computer monitor/screen) that it's not something that can be easily discerned, or else we'd have seen something other than the near-perfect split! I actually hadn't expected it to come out so even.

If anything, though, I'd say there's less of a noticeable difference in person with both knives in hand. :p
 
Larrin said:
The old school method for checking steel type is a spark test not visual inspection of the surface. If the old timers couldn’t do it I highly doubt anyone is now.
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Yep the spark test is a good’un. I’d prefer a hand-held laser mass spectrometer but I don’t have the 25 grand for that right now. X)

Just for argument’s sake, the whole point of all my yammering on the subject is that it is possible to see a certain very subtle difference in iridescence due to all that chromium and/or it’s effects, IMO, not that it’s a reliable way to sort the alloys, or is even easy or convenient.

What spawned the whole thing for me was that the notion of someone preferring the “look and feel” of carbon over stainless steel knives was being treated as preposterous. It’s not preposterous; many people prefer one or the other due to extreme subtleties within alloys or because of the general way certain alloys are worked. They look and feel different!
 
FortyTwoBlades said:
As previously noted, this was all purely anecdotal/casual rather than scientific. But it does at least provide some small evidence that for these conditions (looking at a static photo of the two knives, taken in natural overcast lighting with a DSLR camera and viewed on a computer monitor/screen) that it's not something that can be easily discerned, or else we'd have seen something other than the near-perfect split! I actually hadn't expected it to come out so even.

If anything, though, I'd say there's less of a noticeable difference in person with both knives in hand. :p
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I for one appreciate all the good arguing and the fun thread, FortyTwo. If I ever get to visit your machete paradise, I will attempt to pick out the stainless steel from a lineup just to see what happens.
 
danbot said:
I'll check again tomorrow and look for the irredecence. I love looking at them anyway!:)
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It looks like how trout scales gleam, with a rainbow haze. Try using a loupe maybe, at an angle. The shimmery rainbow is more robust than normal steel because of some prism effect on the surface, but maybe it’s just madness and everyone is licking and salad-fingering and staring closely for nothing.
 
Mecha said:
It looks like how trout scales gleam, with a rainbow haze. Try using a loupe maybe, at an angle. The shimmery rainbow is more robust than normal steel because of some prism effect on the surface, but maybe it’s just madness and everyone is licking and salad-fingering and staring closely for nothing.
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I have a set of loupes at work!:thumbsup:
Everyone there thinks I'm crazy already, so it won't be too weird to stand in the parking lot staring at my knives through a jewellers loupe!:thumbsup:
 
danbot said:
I have a set of loupes at work!:thumbsup:
Everyone there thinks I'm crazy already, so it won't be too weird to stand in the parking lot staring at my knives through a jewellers loupe!:thumbsup:
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Excellent!
 
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