1. Stacy E. Apelt - Bladesmith

    Stacy E. Apelt - Bladesmith ilmarinen - MODERATOR Moderator Knifemaker / Craftsman / Service Provider

    Aug 20, 2004
    Posting this in parts due to length:
    W2 gets a lot of talk, but to most it is a bit of a mystery.

    Some comments from those who use it will help others with learning and working this steel. I will link this thread to the HT sticky.

    If you are an experienced maker who uses W2 and are proficient with forging and HT, post your advice and observations.

    If you are still learning - and we are all still learning - and have specific questions, post them here, too.




    I'll start off with some basics:


    W2 isn't an exact content description. The "W" means it is a water quench steel, and the "2" designates it as a little different from W1.
    Generally, W2 has high carbon content, but that is not a guarantee. If bought from a knife supplier, or using a known and analyzed batch, then the carbon content can be relied on. If you just buy W2 from a steel supplier, it can range from .80% to nearly 2% carbon.

    Most knife grade W2 has around 1.5% carbon. Manganese is usually around .40%, but it can be lower. It is the batches with the lower Mn content, that knifemakers love. There are various small amounts of chromium, nickel, tungsten, and vanadium in W2. W1 has less vanadium. In many cases, both steels get called, and sold as, W2. This is why you want an analysis of the exact batch you are buying.

    Because of this variability, and the tricky nature of HT for W2, when you find a batch you like, it is a really good idea to buy as much of it as you can. This is why guys like Don Hansen, and formerly Bill Moran, bought it in thousand pound batches. Label it and keep it separate from other batches of W2. You will read and hear about makers hoarding Don's W2 like it was gold bullion. To many makers, that is close to what perfect W2 is. I never thought of it before now, but I have hundreds of dollars worth of expensive steel sitting openly in the smithy. Don's W2 stash is locked in the storage building with the HT ovens and valuable stuff.

    Because of the makeup, W2 is very shallow hardening, and must have a very rapid cooling rate in quench. It must drop from 1450°F to below 1000°F in less than one second. This requires either a fast oil, like Parks #50, or water. Water/brine will certainly harden W2, but the risk of cracked and broken blades is high. Most makers use the fast oil. Alternate oils and concoctions just won't work for W2.

    The shallow hardening and rapid quench rate make W2 great for attaining an active hamon. It may take dozens to hundreds of trial and error attempts, but once you zero in on the HT and clay application (some makers use no clay), you can attain amazing hamon patterns. This is because the steel exposed to the quenchant will miss the pearlite nose and go on as super-cooled austenite (until it converts to martensite at the Ms) while the steel under the clay and near it will change into pearlite. The boundaries of these two structures creates the hamon.


    W2 forges well.
    Like most high carbon steels, use lower austenitization temps. A forge can be used, but an oven is far better for W2. You may end up picking a very exact temperature that creates a hard edge and amazing hamon. It isn't unusual for numbers like 1437 degrees F (eg.) to be used by some makers. Since all equipment reads and operates a bit different, you will have to find your own magic number, Just because Don or Chuck get good results with 14XY° doesn't mean you will get their results. You may have to use 14YZ°.

    W2 isn't a magic steel, and it has not particular attribute ... beyond being good for hamon. It will harden to Rc 65-66 as quenched. And can be used at Rc 64-65 for slicers. Lower hardness down to Rc 62 is used for more rugged knives. If just getting started, shoot for Rc 63-64. Edge retention and toughness are not why you pick W2, so if they are of prime importance, another steel would be a better choice. One of the main advantages of W2 is that it is cheap and readily available.
     
    Last edited: May 20, 2016
  2. mete

    mete

    Jun 10, 2003
    W1 vs W2 ? W2 has that stuff called Vanadium ! Small amount but it's enough to make a significant change .Vanadium likes grain boundaries .It makes grain boundaries resistant to movement .That movement makes for grain growth ! So we then have a smaller grain size , good for strength and toughness . W2 still has the hardenability of W1 so hamon would be the same but better properties . I like it !
     
  3. Stacy E. Apelt - Bladesmith

    Stacy E. Apelt - Bladesmith ilmarinen - MODERATOR Moderator Knifemaker / Craftsman / Service Provider

    Aug 20, 2004
    Phishtopher likes this.
  4. Willie71

    Willie71 Warren J. Krywko. Part Time Knifemaker Knifemaker / Craftsman / Service Provider

    Feb 23, 2013
    I asked Kevin Cashen why W2 was better for a hamon than 1095, with similar carbon and manganese numbers. He told me the effect of the vanadium in the steel created the extra activity. Aldo's W2 is quite similar to Don's. It was smelted based on an analysis of Don's stock iirc. Don does have that W2 with the alloy banding though. I regularily get Rc67/68 with this steel. Great stuff. Great edge stability and edge retention.
     
  5. Don Hanson III

    Don Hanson III KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Oct 3, 2002
    Good thread Stacy. Your as quench numbers are a little low.
     
  6. J. Doyle

    J. Doyle Bladesmith/Knifemaker

    Feb 17, 2008
    Don, are you sure you're qualified to speak on this matter? :D ;) :p
     
  7. jdm61

    jdm61 itinerant metal pounder

    Aug 12, 2005
    In addition to get harder than it is supposed to and taking a ridiculously fine and stable edge, Mr. Hanson's W2 appears to have a bit more abrasion resistance than it should even though it is supposed to only have enough vanadium to control grain growth. Nothing quite like CruForgeV, but definitely there.
     
  8. Stacy E. Apelt - Bladesmith

    Stacy E. Apelt - Bladesmith ilmarinen - MODERATOR Moderator Knifemaker / Craftsman / Service Provider

    Aug 20, 2004
    Thanks, Don.

    We would love for you to post your W2 HT regime and any tips you have on working it.

    I find most W2 hardens to around Rc66 as-quenched. Probably because it auto-tempers a bit when I pull it out after 5-8 seconds to check for straightness.
     

  9. yes yes yes please!
     
  10. Don Hanson III

    Don Hanson III KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Oct 3, 2002
    That could be it Stacy. I hold in the quench for 10 seconds then pull out and check. I always get 67.5 - 68.5 Rc out of the quench with
    'this' W2. 'Other' W2 I've tested has come out 1-2 points lower.

    OK, I start out forging W2 bars at high heat, around 2000f. As I get closer to final size / shape I reduce heat progressively. Last
    forging heats will be around 1500-1600f.

    Then normalize three times in the forge being very careful not to over heat, tip out the back door & a very even heat. First just above
    critical, then at critical, then just below critical. I use the forge because it is fast and I get no noticeable decarb. Use oven if you can't
    judge temps using forge.

    If normalizing & austenizing with electric oven with long soak times, coat the blades or be prepared to grind off decarb.

    Austenizing, using electric oven I like 10 minute soak at 1460f. Quench in room temp Parks 50.

    In forge I judge temp by color in semi dark shop with years of practice. I quench on a rising heat with no soak time. I've tested blades
    done in oven vs forge and can't tell any difference. These results can & will vary widely from one shop to another.

    Tempering; I used to temper W2 blades for one hour twice, lately I've bumped the time up to two hours, just because. 400f will give me 64-65, 425f 63-64, 450f 62-63. I usually run smaller blades at 425 & large knives at 450. Have never had a W2 blade chip or crack at these high Rc numbers.

    Very Thin edge stability is pretty amazing & edge retention is better than any other simple carbon steel I've used.
     
    calcasieu and coldsteelburns like this.
  11. samuraistuart

    samuraistuart KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Dec 21, 2006
    WOW, did ya'll catch those temper numbers Don's getting with his W2? Wow! Using the "other" W2, I'm getting around a point or two lower, just as he indicated. 430f temper puts me around 62 (guessing that number, by a file. if my file is around 64-65, then I'm getting around 63HRC with 430f).
     
    Last edited: May 21, 2016
  12. Phillip Patton

    Phillip Patton KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Jul 25, 2005
    I hope I'm not changing the subject here, but Don, do you know the carbon content of your w2? Thanks for your input so far! You too, Stacy. Good stuff!
     
  13. Don Hanson III

    Don Hanson III KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Oct 3, 2002
    Phillip, specs below thanks to Russ Andrews.

    C .95,
    Mn .22,
    V .19,
    Cr .15,
    Si .23,
    Mo .013,
    Ni .08,
    Cu .14
     
  14. Willie71

    Willie71 Warren J. Krywko. Part Time Knifemaker Knifemaker / Craftsman / Service Provider

    Feb 23, 2013
    I'm getting the same numbers after temp as Don, with Aldo's W2. I have my austentizing temp nailed for my kiln, with DT-48. I just did an 8" chef's knife in brine, and the Rc# was 0.75 higher than the DT-48 using an average of 10 tests. Non interrupted quench. Puckered my lips and it held together. :eek: I tempered at 440 to get Rc63/64 with the brine. I did a 1095 knife the same day, and can't get consistent readings on the tang. The 1095 knife was ground before heat treatment where the W2 knife was thin, and austentized after profile. I broke the last two blades in brine, so I added a 1400f extra cycle after the 1450. I quench after the last cycle cools to magnetic in medium oil. For brine I use a wash of clay over the whole blade, then clay up for the hamon.

    I'm not recommending brine to anyone. I'm trying to get better hamon activity out of 1095, as I can get thin 1095 quite easily for chefs knives. If I can maximize the esthetics, I can use it as an alternative to W2. If not, it will just be a less expensive option and I won't spend as much time bringing out the finer details.
     
  15. Phillip Patton

    Phillip Patton KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Jul 25, 2005
    Thanks!

     
  16. Willie71

    Willie71 Warren J. Krywko. Part Time Knifemaker Knifemaker / Craftsman / Service Provider

    Feb 23, 2013
    Don, I wanted to thank you for sharing your heat treat info again. You put me on the right track to get the best results in my shop, and you didn't have to do that. Some people are just good people. :thumbup: :cool: :)
     
    Justin Schmidt likes this.
  17. S.Alexander

    S.Alexander

    Jul 7, 2013
    I have noticed that on thicker pieces of W2 steel, I will get an auto-hamon after quenching in Parks 50. I understand in basic terms why this is happening, due to the steel being shallow hardening. Can someone explain in more detail how an auto-hamon occurs?
     
  18. Tom Lewis

    Tom Lewis

    Feb 24, 2000
    This is a very informative post. I have a question that maybe Don has already answered.
    Does W-2 need a ten minute soak before quenching?
    I did a test as the picture shows. The blade on the left had a ten minute soak in my paragon at 1460 degrees before quenching in Parks 50. The three blades on the right were heated with a torch to just above non magnetic,and just the bottom half was heated before the quench. Everything else about the four blades was the same. The three blades heated with the torch have a better hamon. This was a quick polish and etch of maybe ten minutes for each blade.
     

    Attached Files:

  19. me2

    me2

    Oct 11, 2003
    The auto hamon is because the thicker portions don't harden at all, virtually. You'd think there would be a hardened skin on the outside. However in pieces as thin as knives, the cooling rate at the center of the bladder is essentially the same as at the surface. So you have kind of a line on the blade. Thicker than the blade thickness at the line and it won't harden, thinner and it will. For a steel like W2, thicker areas wiki be fine pearlite or something like that, and thinner areas will be martensite. You can sometimes see the line without polishing, but it really comes out with proper polish.
     
  20. Don Hanson III

    Don Hanson III KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Oct 3, 2002
    You do need to soak W2 for at least 10 minutes if elec oven is used. I don't soak when using forge or torch, have a couple W2 knives I use daily that were torch quenched and they perform very well... Do some cutting tests with the blades you have there and see if there's any difference.
     

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