Knife Steels

Replies to This Discussion

Permalink Reply by kage on September 10, 2010 at 15:07

As with most things, what's best in knife steel will be determined by blade design, intended use and environment.

ZD 189 can either come in as a folded laminate or as straight stock. If as a laminate, the outer fold/sleeve will be a softer steel. This can be prone to scratching on the blade face. ZD 189 is composed mainly of high levels of Carbon and Chromium, so it would be good for moist/salty environments. But it also makes a chore out of re-sharpening and honing. A thin edge (13° - 17° bevel angle) and either a long blade (such as a fillet knife) or a short blade (such as a carver) would be better suited for this steel.

CPM M4 is a high-end tool steel composed with high quantities of Chromium, Molybdenum, Vanadium, and Tungsten, which contributes to its industrial nature/usage. One could regard such a steel as basically a "super carbon" steel, and its applications would be utilized in the same manner as one would use any such high carbon blade (such as in Bushcraft, Camping, or other extreme hard use endeavours) in moderate environments (with a 15° - 20° bevel angle.)

D2 is another tool steel with slightly more Carbon and Chromium than M4 and is often described as a "semi-stainless steel." This steel involves an air hardening process, as opposed to the more common liquid cooled tempering of other blades. As such it is stronger and less brittle than other industrial steels, so would be more suited for outdoor usages in colder climates with a 25° - 30° bevel angle.) Its high Chromium content allows for greater rust resistance over that of other Carbon blades.

Hope that helps.

Permalink Reply by Patrick Tetangco on September 13, 2010 at 10:35

That helps a lot! Thanks!!

I'm asking because I was thinking of buying either a Spyderco Stretch in ZDP 189 or a Spyderco Gayle Bradley Carbon Fiber in CPM-M4.

I also have a Benchmade Nitrous Stryker in D2 and I wanted to find out if I could EDC it. I'm concerned about it not being a stainless steel because it misses the amount of chromium needed to be such a steel by 1%.