stainless vs carbon - how do you tell?

Discussion in 'Straight Razors' started by RocketMan, Feb 12, 2009.

  1. RocketMan

    RocketMan Member

    I am trying to understand more about the steel used in razors. Specifically, how to tell the difference bw stainless and carbon steel. I thought that the very shiny ones were stainless, and the sort of duller ones were carbon. (I recently picked up my first str8, an Ern, which is in fabulous shape, but very shiny, almost chrome like, so I am assuming it is stainless)

    It is my understanding from Wikipedia that stainless steel wasn't in use really until the early 1900s. Then I came across the razor below which is from Rakowski's web site and indicated to be a thiers from 1884. Yet it is so very shiny that I would have assumed it is stainless steel. Can anybody set me straight on this please?
  2. RocketMan

    RocketMan Member

    Sry - I can't seem to get the link to work

    It is on this page, under straight razors, fourth one down called circa "1884 pink ivory straight razor "
  3. JimR

    JimR Active Member

    Shiny does not equal stainless--which is what threw me at first. It is perfectly possible to polish a carbon steel blade to a mirror finish...
  4. Jimbo

    Jimbo New Member

    That is quite true from what I understand - you cannot tell a stainless and a carbon simply by looking at them unfortunately.

    I really have no metallurgical knowledge beyond the fact that stainless are a steel alloy with some percent of a certain element (chromium??) in it.

    Unless the blade is marked in some way as being stainless (e.g. Friodur, INOX - not sure if that is actually a correct useage, but I think I have seen that on some stainless Dovos) I would work on the assumption that it is fully-corrodable carbon steel and treat it that way. Better safe than sorry.

    I flatter myself that I can usually tell the difference between carbon and stainless steel on the hone, as I feel the stainless types are harder, or more brittle, and generally take longer to hone than carbons. I really do not know if this is true, but like I said I do flatter myself that I can tell :D

    One other thing I have noticed is what happens when you try to apply cold blueing solution to stain resistant razors. Nothing! Whereas when you do the same to carbon steel razors, they blue, of course. Given that you can get blue remover from the same place you get blueing solution, that may be a nifty little test if you are ever uncertain.

    And of course, there is the ultimate test. Stick it in brine, or leave it outside for a few days!! That'll sort the carbon from the stainless!! :happy102

  5. hoglahoo

    hoglahoo Yesterday's News

    Well, it turns out all my razors are carbon steel. Thanks James :mad:
  6. Jimbo

    Jimbo New Member

    But now you know, right? :D

    Actually, after pondering it a little more, you are sort of correct in your initial post. Shiny is a necessary, but not sufficient, condition for determining a stainless razor...

    What I mean is, an old carbon steel razor that has been sitting around for some years will probably have some degree of rusting or staining or whatever, whereas a stainless in a similar position will not. So I guess if you do ever run across an old, darker, stained blade, you will know it is carbon.

    But if you run across a shiny-bladed straight with no staining or marks, you cannot say for certain whether it is stainless or whether it is just a carbon that has been very well looked after, or restored.

  7. RocketMan

    RocketMan Member

    Thnx - I didn't realize that. I guess it is time for me to do a little research and try to understand the differences. I really did always assume the bright lustre meant SS, so this is really helpful. I was a little puzzled because I think my Ern Eagle and Snake razor is older than 1910, so maybe I got lucky and just ended up with a really well kept item! I don't think it has been restored because the gold wash on it is excellent. I am amazed how much there is to learn regarding shaving and the history involved - a truly fascinating topic.
    jimmie likes this.
  8. moviemaniac

    moviemaniac Tool Time

    Just put a drop of lemon juice on a less noticeable spot. If it leaves a black spot, the razor is made of carbon steel.
    178-bplatoon likes this.
  9. RocketMan

    RocketMan Member

    If my str8 turns out to be carbon, the only mark on it in a hundred years would be the one I made! Would this clean off easily afterwards or would the 'stain' be permanent? Seems a little like throwing the baby out with the bathwater - but seems like a great tip.

    thnx moviemaniac
  10. Jimbo

    Jimbo New Member

    That *is* a great tip! Thanks Klaus! :1respect

    Having never done it, I do not know whether it would clean off easily or not. Best wait for Klaus to get back to you on that one. Sounds like a homemade version of bluing to me though, so I imagine it would come off.

    If you were to do it, I would suggest, as Klaus said, somewhere reasonably inconspicuous. Like the underside of the monkey tail, for example.

  11. moviemaniac

    moviemaniac Tool Time

    No worries, guys :D I saw that test in an episode of CSI Las Vegas :rofl

    But I just tried it: It works and really doesn't harm the blade. The best way to do this is to wet a toothpick and stick it into a pack of citric acid. Then place the moistened crystals that have attached themselves to the toothpick on a secluded spot like the tang. You might want to add a drop of water with the other side of the toothpick. Let the stuff sit there for a coupla seconds (around 15). Wipe off. You're gonna see a faint reaction on the blade that'll clean off easily (I tried Never Dull - works perfectly).

    Sometimes you can really learn some stuff from those TV-shows :D
  12. Jimbo

    Jimbo New Member

    Doesn't matter where you got the idea Klaus - it is a great one! I am certainly going to try it the next time I run across a razor of unknown steel type. Thanks!

    But yeah, BSI (Bathroom Shave Investigation) forensics could be the next big thing.... :happy102

  13. PalmettoB

    PalmettoB The Old Guard

    I'm going to make this a sticky. Or maybe we need a Wiki. Hmmm...
  14. moviemaniac

    moviemaniac Tool Time

  15. Leon

    Leon Active Member

    Hmmm... anyone wants to try this test on a Filarmonica 13 from CS? Although it's commonly stated as being HCS, some say that this razor is SS, that would explain why they're more difficult to hone than other Fillies.
    Of course, this particular razor, being the last batch of the Filarmonica factory might just have more carbon in the alloy than its previous versions and not necessary be a SS razor.
  16. Tony Miller

    Tony Miller Member

    Most, not all good stainless is really stainless and will not rust. Some cheap import stainless knives will corrode over time as the stainless elements are in short supply in the cheapies.

    The easiest test.....most, stainless is not magnetic. The nickel used in most stainless inhibits the magnetic qualities of the steel, some stainless has chromium and no nickel and will possibly attract a magnet. Much depends on the specific series of alloy but as a rule, if a magnet sticks it is usually not stainless.

    (Please note that as Joe pointed out the stainless used on knives is a series of stainless that is indeed magnetic, unlike many of the more utilitarian grades. I stand corrected as I had no idea what type of stainless knifemakers used vs. that used for other applications.)

  17. Joe C

    Joe C New Member

    I'll generally use a drop of gun blue, but the concept is the same, and your idea is way cheaper. lol Good one. Any acidic liquid will work.
  18. Joe C

    Joe C New Member

    Tony, this isn't accurate. Every knife quality stainless is magnetic. Every one. Nickel isn't the element that makes a steel stainless. It's chromium, and over 12%. If a steel isn't magnetic, it's austenitic and isn't hardenable by heat treating. Thus, it would be incapable of being made into a knife (or razor). Any martensitic stainless steel (capable of being hardened by heat treating; i.e., a steel capable of being made into a knife) will attract a magnet. And stainless will rust. It's stain-less, not stain-free, and it would take longer, but it will stain, corrode, and rust over time if not properly cared for. It certainly doesn't require the same care and attention as a carbon steel blade. I'm glad you posted this, as it clears up a common point of confusion when it comes to steel.
    Radiotube likes this.
  19. Tony Miller

    Tony Miller Member

    I may be wrong on what stainless is used in knives but in general the non-magnetic applies to stainless for other applications.

    Both nickel (in 300 series SS) and chromium (in 400 series SS) are used in stainless for various applications. The nickel laden series is not magnetic, the 400 is.

    Which is used in knives I have no clue, so there I stand corrected.

  20. Joe C

    Joe C New Member

    420 (420HC and 420 modified) and 440 (440a, 440b, and 440c) series stainless steels are used in blademaking, with 420 being the minimum. Both are magnetic, martensitic stainless steels. In short, if it's not magnetic, it's not suitable for blades, either knife or razor. The 300 and 400 series (like 416) is used strictly as decorative steels (like bolsters) or as kitchen equipment, like steel countertops and sinks. :) Neither is suitable for, nor used as, blade steels. Knives and razors use the same type of steel, with razor steel usually tending toward the higher carbon content steels.

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