Just what are those speed skating blades made from?

Discussion in 'Shop Talk - BladeSmith Questions and Answers' started by Larrin, Feb 10, 2018.

  1. Larrin

    Larrin Gold Member Knifemaker / Craftsman / Service Provider Gold Member

    Jan 17, 2004
    The blades in hockey skates are their own separate thing and I'm not ready to dive into that world yet.
     
  2. Willie71

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

    Feb 23, 2013
    Only Canadian Metallurgists are qualified to deal with hockey skates. :eek:
     
    Knife freaky, Geoff Flato and Larrin like this.
  3. kuraki

    kuraki Fimbulvetr Knifeworks

    Jun 17, 2016
    We already know the secret alloying ingredient is All Dressed chips powder.
     
  4. Neo

    Neo

    Sep 12, 2002
    Are K490 and K890 close in wear resistance?
    [​IMG]

    How would K490 compare to Va4E ?
     
  5. Larrin

    Larrin Gold Member Knifemaker / Craftsman / Service Provider Gold Member

    Jan 17, 2004
    Those two steels are in the same general category: they both have 1.4C and 3.7V, with differences in the Mo, W, and Cr contents. The K490 also has a niobium addition. Despite Bohler and Uddeholm being owned by the same parent company they operate relatively independently; they generally don't compare their steels to one another. Despite some dubious language about testing direction in the datasheets, I believe both are transverse unnotched izod tests. In the datasheets K490 is listed as having 80J at 62 Rc (https://www.bohler-edelstahl.com/media/K490DE.pdf) while Vanadis 4 Extra shows about 58J (https://www.uddeholm.com/files/PB_Uddeholm_vanadis_4_extra_english.pdf). However, in the patents K490 shows about 78J for 64 Rc and 87J for 58.5 Rc (https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US20100233500.pdf) while Vanadis 4 Extra got 102J for 60 Rc (https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US7297177.pdf) So again I think the best we can say is that they are in the same general category. I'm not sure why the patent shows better toughness than the datasheet does for Vanadis 4 Extra. The datasheet for Vanadis 4 Extra clearly indicates they are transverse tests, but the patent just says "LT2" direction which I can't find a reference to anywhere else. Maybe the patent used a longitudinal direction test? I'm getting too far in the weeds now.
     
    Last edited: Feb 12, 2018
    Neo likes this.
  6. mete

    mete

    Jun 10, 2003
    I'm not a skater so it's all a mystery to me. I had read that skates are hollow ground .Not like a knife but like the drawing in the article so you are skating on two edges .
    There are comments about directionality in steels in the forum.The Crucible info states that much of the improvement in toughness in CPM steels is in the transverse direction .Most, though not all steels show directional properties upon rolling. This is dealt with by 'cross rolling' and Matt's report on his trip to NSM was that the Crucible CPMs are cross rolled .The difference in properties vs rolling direction can be significant ! The steel strip is cut into squares and each time you roll it you turn it 90*. Certainly it would show upon skate blades. I think in Viking days they used a piece of bone !!
     
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  7. erik markman

    erik markman

    Aug 13, 2007
    Speedskates have a square edge. Hockey and figureskates are hllowground and thicker.
     
    Willie71 likes this.
  8. Willie71

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

    Feb 23, 2013
    The scientific mind at work....
     
    Ken H> likes this.
  9. Danke42

    Danke42

    Feb 10, 2015
    And they for sure get sharpened differently. Way back decades ago I used to be in a store that did hockey gear in the winter and you'd spend your Saturday in the booth sharpening skates. It was very easy to do, the skate clamps in a guide that you hold against the grinder and make as many passes as needed using the right touch. These were mostly kid's hockey skates so they didn't need sharpening because of skating; they were dull because the kids would wear them on hard floors. You'd see maybe one set of figure skates a month and they were a nightmare since those parents were much worse than the hockey parents for complaining about how little Jennifer didn't get a trophy because her skates were badly sharpened. They were followed by the parents of goalies, then the regular players. We never once saw a set of speed skates despite having a fairly established program in the city to the point of locals medaling at the Olympics.
     
  10. Neo

    Neo

    Sep 12, 2002
    Thank you very much.
    The slightly higher amount of Cr in K490 might result in slightly less toughness.
    Nb and W in K490 should increase the amount of carbides in comparison with Va4E and increase the wear resistance?
    Higher carbides amount also decreases toughness?
    I would love to try this steel.
     
    Last edited: Feb 13, 2018
  11. Larrin

    Larrin Gold Member Knifemaker / Craftsman / Service Provider Gold Member

    Jan 17, 2004
    It highlights the problems with trying to get good data from datasheets (sales) and patents (lawyers).
     
  12. Larrin

    Larrin Gold Member Knifemaker / Craftsman / Service Provider Gold Member

    Jan 17, 2004
    I'm not sure if the Cr will make a difference, it may or may not. The niobium addition to the K490 was made for the purpose of refining the overall carbide structure to improve toughness rather than to add wear resistance but it is possible there is a small increase.
     
  13. Willie71

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

    Feb 23, 2013

    I agree. I spend a lot of time weeding through crap to get the real information in the field of mental health.
     
  14. Lapedog

    Lapedog

    Dec 7, 2016
    That’s not true. I see at alot of skating rinks up here “automatic skate sharpening machines” you just load your skates in and put in money and it sharpens them for you.

    However it looks like they mostly overheat the skates judging by the way they work and the sparks they throw.


    Skis and snow boards have a metal edge around the outside edge of them. The board itself is not made of steel.

    Seen here.
    [​IMG]
    Here is one coming out of the ski. (It needs to be repaired)
    [​IMG]


    Knives get overheated all the time when sharpened with powered systems. There are plenty of instances of knives with edges that have been compromised by overheating while sharpening. Once you sharpen them a few times and reach the unaffected steel underneath the knife takes a better longer lasting edge.
     
  15. erik markman

    erik markman

    Aug 13, 2007
    In Holland speedskates are manually sharpened. Like I said the only time the are put in a machine is when they come from the factory and they do not have the neccesary curve in them.
    And we kick all the asses in speedskating....
     

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