Steel attributes question?

Discussion in 'New to Knifemaking' started by Kev, May 18, 2017.

  1. Kev

    Kev Well-Known Member

    Which attribute (or combination)of a particular steel directly translates to edge holding ability? For example toughness vs. abrasion resistance vs. wear resistance, etc. I've been doing my due diligence and trying to study up on the different properties of various steels. I have a laymen understanding of what the different values mean, I'm just struggling to understand how the different values translate into knife qualities.
     
  2. Smallshop

    Smallshop KNIFE MAKER

    Kev....search Kevin Cashens posts. He is very technical in knowledge but very gifted in communicating said knowledge to the average joe.I print some things he has written so I can review. Anything that he has written that I have applied seems to be spot on.
     
  3. EdCaffreyMS

    EdCaffreyMS Forum Owner - Moderator

    There's much more to it then just a simple answer .... Particular alloying elements impart specific characteristics, both by themselves, and in combinations with other alloys. Just because certain elements are present in a given steel, doesn't necessarily mean you will realize the characteristics they offer....at least not all the time. It's up to the individual knifemaker to "bring out" those charaterstics bases on how the steel is handled (how it's ground, heat treated, etc).

    Here's a simply page on my website that attempts to explain alloy content found in steels, and the basic characteristics they impart.... http://www.caffreyknives.net/element_content.html

    As I often say, knifemaking always seems to be about "give-n-take"..... when it comes to alloying elements present in steel, it's not uncommon to gain a certain characteristic when choosing to use a steel with certain alloying elements, but at the same time loose/give up a given characteristic in another area. It can be a "balancing act".

    I wish I could give you direct specific answers to your question(s), but they would only be generalizations..... there are just too many variables, I will simply direct you to the above link.
     
  4. Kevin R. Cashen

    Kevin R. Cashen Super Moderator

    I was asked to have a look at this question so...

    Here are some of the reasons certain elements are added to steel:

    Carbon- it is what makes iron into steel, from .55% up to .60% you will have a naturally tougher blade that will not hold a really fine edge for long but will do well on beefier edges that can chop. From .70% to .80% the edges will be high hardness and do a wide variety of tasks. From .85% up to 1.2% (or a little higher) the steel is best for fine slicing edges that will have a higher abrasion resistance for edge holding, but will not tolerate chopping of other abuse. This is what carbon will want to do naturally but a skilled heat treater can move the carbon around and use what he wants in different ways, so one could make a 1% C steel behave like a .80% steel if you have good control.

    Manganese- in lower levels it is just there to render sulfur contamination harmless, but it can be added in higher levels to increase hardenability. It has a reinforcing mechanism on the structures in the hardened phase of steel that can be good, or bad, depending upon how you look at it. At 1% or higher the steel is a deeper hardening alloy.

    Chromium- is the go to for industry for increasing hardenability or, when added in massive amounts lending stain resistance. It will give you some abrasion resistance from its carbide forming properties, so when you have higher carbon levels mixed with it you can have a very fine edge that will wear well. In lesser amount it can refine grain and not form heavy carbides.

    Vanadium- a very powerful alloy element, just a pinch ( .2%) will keep grain nice and fine and above that you need to add more carbon because of how hungry V carbides can be, but the abrasion resistance can go through the roof. Blades with vanadium in them take an edge that makes my hair stand on end when I feel it. Great for fine slicers, not so much so for heaver edges on choppers.

    Tungsten- great for abrasion resistance, and will raise tempering temperatures as it is often used to increase the life of steel that could get hot in high speed applications, as is the same for molybdenum.

    Nickel- the toughener of the bunch. Nickel is the best way to make a steel take a pounding as a large chopper, but it also has some side effects that make you want to keep the carbon levels at around .75% or lower. In higher doses it takes stainless to all new levels for laughing at corrosion but it does so at the expense of hardenability, and is what gives the nonmagnetic quality to austenitic stainless. In simpler steels it will usually be in the range of 1% to 1.4% for excellent toughness.

    So for fine slicers- higher carbon, vanadium, chromium, or even tungsten. For heavy choppers- lower carbon levels, chromium at lower levels and nickel, oh and I forgot to mention silicon which is also very good for taking a beating.
     
    Last edited: May 19, 2017
  5. me2

    me2 Well-Known Member

    Which material property to look for depends on use of the knife. You'll need high abrasive wear resistance for cutting things like used carpet. You need high toughness for things like chopping knives, bush knives, machetes, etc. High strength allows a thinner edge for cutting without edge rolling.

    A chopping knife with low toughness can dull by getting small chips, a low abrasive wear steel will dull very quickly when cutting used carpet. Low strength will dull by rolling when sharpened to a fine edge for something like precision cuts in leather work. It helps to know the uses of the knife and the various ways edges dull, as there is more than one way.
     
  6. jaxxas

    jaxxas Well-Known Member

    Tagged!
     
  7. Justin Presson

    Justin Presson Well-Known Member

    Kevin that was some great info explained in terms that I can easily follow. Thanks for the info!

    Sent from my SM-G920P using Tapatalk
     

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