Hey Nathan, which type of steel would you prefer for a DEK3 with sharpened top edge, modified D3V or Magnacut?
Nathan the Machinist
I'm very partial to Delta 3V but Magnacut is a pretty interesting material and the DEK is a good application for it. Personally, Delta 3V. I don't need salt level stainlessness, I'm primarily concerned about my knife's ability to remain sharp without damage in my normal use and so far D3V is still king there.
People have an amazing inability to understand what edge retention actually is. It seems self explanatory, but apparently it's not. It's like toughness vs durability.
Durability is usually related to strength and strength is inversely related to toughness. So when I see someone say that a material has the toughness to shrug off damage such as chipping or rolling they're not talking about
toughness at all (quite likely the opposite). It's durability (a combination of ductility at high hardness and strength), but "durability" is not a well defined term with an objective number or value which is what makes it so difficult to have discussions on the internet with people because you never know where someone is coming from and their experience and understanding on the subject. A lot of the internet is folks who are well read but have little real experience talking about things like edge retention and toughness but using values related to abrasive wear resistance and Charpy impact testing.
The Sebenza I carry is S35VN at about 59 HRC. S35VN is an excellent alloy (and at this hardness it is quite "tough") but it's honestly pretty dreadful in their execution in this application. I used it to pry some staples out of wood the other day and it is wrecked where one of my knives could have
cut through the staples with less damage. It has very good abrasive wear resistance values and toughness so on paper it looks pretty good, but in this application it's really pretty bad. It won't stay sharp. My whole company is based on the understanding that this is not good edge retention and there are ways to make knives that perform.
Long segway there, I'm sorry. But the point I'm reaching at is I'm concerned about actual real edge retention (the ability to
retain an edge, duh) and in my experience, Delta 3V is the best choice for me.
There are multiple ways to achieve a given hardness with a given material that will have different properties. Focusing on just the rockwell hardness number is missing a lot of detail
3V is designed as a mostly lath martensite. We normally straddle the line with a mix but we can push the aust temp and time to put enough carbon in solution to form more plate martensite. This approach always comes at the expense of additional retained austenite which almost always needs to be addressed in the primary quench to prevent a mix of problems. We have techniques to address this (it's not just cryo) and we can use a variation of the standard Delta protocol for these hard thin knives that gives this lovely material a little bit more of that crisp edge that performs so well at narrow edge angles. We used it on the OG field knives, it was an option on the hard-thin FK2 and it will be used on the DEK3.
