Spring steel for knife making

Discussion in 'Maintenance, Tinkering & Embellishment' started by TheEdge01, Nov 17, 2019.

  1. TheEdge01

    TheEdge01

    Apr 3, 2015
    Hello guys, one of my co-workers gave me some steel from leaf springs that came off of a 1969 GM truck. He cut them into smaller pieces using a torch, how much of the steel would be damaged from the heat? I want to practice heat treating to so I would like to know what portion of the steel has a damaged temper from cutting it. If possible, could someone tell me what kind of steel it is?
     
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  2. Bill DeShivs

    Bill DeShivs KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Jun 6, 2000
    To properly heat treat, you will have to know exactly what steel it is.
    It may be 1095 or 5120, but you need to know for sure. Perhaps someone here knows, or you could send a sample off to be tested.
     
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  3. Bill3152

    Bill3152

    263
    Nov 27, 2018
    I don't know for sure however I heard that spring steel rusts but doesn't pit due to its composition.
     
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  4. Danketch

    Danketch Gold Member Gold Member

    581
    Apr 27, 2007
    If you are going to forge the knife, then the torch cuts shouldn't matter I wouldn't think, as you are going to be bangin and clangin the whole mess in a furnace/forge first. What should matter is knowing the steel type for afterwards, when you do the heat treat, so you know what "recipe" to follow. I haven't done any of these, but I always hear 5160 was the generally accepted steel used for most leaf springs.
     
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  5. Bill DeShivs

    Bill DeShivs KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Jun 6, 2000
    Any carbon steel can rust and pit.
     
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  6. David Martin

    David Martin Gold Member Gold Member

    Apr 7, 2008
    Yes, a leaf spring will be made from a simple steel. Especially from 1969. Not likely 01. The heat treat can be simple. Be sure to temper twice. If it is hard to file you may need to anneal it. DM
     
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  7. mross

    mross

    327
    Nov 10, 2003
    I'll second the 5160. If you anneal it and start from scratch I don't think the torch cut will matter.
     
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  8. HopalongCassidy

    HopalongCassidy

    49
    Sep 22, 2019
    I’ve made lots of tools out of “spring” steel. You will never know what you are working with for sure. The cuts will not matter as you will reheat and anneal.
    Your quenching and tempering will be trial and error; you can file and look for your colors, but it’s still a guess. Quenching medium and heat is a guess as well.
    Even your heating is a guess by color, and method. Coal, gas; soaking or surface heat.
    Trial and error. After a while you get a “feel” for what you are working with.
    In the end, I was often surprised by what I was working with.
    If you’ve got a lot of the same stuff you can make your adjustments.
    I learned to enjoy the process.
     
  9. HopalongCassidy

    HopalongCassidy

    49
    Sep 22, 2019
    Here is an anecdotal example of “you just don’t know”
    My apprentice of 12 years went on Forged And Fire a year and a half ago.
    Incredibly talented, a superb craftsman.
    We are farriers, not knife makers, but we hand forge. We use hammer, anvil, and tongs.
    Although we do use grinders and sanders, our stuff is closely finished by hammer.
    Anyway, the contestants were to pick from a table, the steel to be used for a knife.
    Tyler drew last, and got stuck with some spud wrenches.
    He hand forged a beautiful knife, but couldn’t get the steel hard.
    He reheated re quenched, several times. Nothing.
    Most likely cheap Harbor Freight Chinese steel.
    Even the judges said the steel most likely could not be hardened.
    He was eliminated. The guy that won, had picked the farrier rasp.
    He cut and ground a knife. No forging, no anvil, hammer or tongs.
    Lol. Enjoy the process. Tyler made the nicest knife, and everyone knew it.
     

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