Friday, August 14, 2020

Knife steel

I am not a purist when it comes to knife steel(s).

Custom knife makers have done a great deal to popularize some very exotic steels. Many of these steel alloys have their origins in the aerospace industry. Others were spawned by the need for ultrasmooth bearings for hard-drive data storage devices.

Personally, I think any steel that can be hardened to 55 Rockwell C makes a fine knife. In a pinch, I would even say 40 Rockwell C which is spring/high-strength bolt territory. Maximum hardness in most steel alloys is dominated by the the carbon content.

Most other alloying elements are added to steel to increase depth of hardening. That is, so thick sections of steel reach full hardness through their entire thickness. Knives are rarely thick enough to require anything beyond the normal amount of manganese in common "carbon steels" to reach full hardness. That means that any steel with more than 0.50% carbon will reach the ERJ approved level of hardness.

So there you have it, any grade of steel with 0.50%-through-1.5% carbon will get it done.

Most of what I cut with a knife is not very challenging. Cords, green branches, weeds, food and the like. When my knife gets dull I sharpen it. Exotic alloys are not needed for what I do. I don't need "massive carbides" or "excellent hardness at 1400F" to cut cabbages.

I even find the use of stainless steel to be a bit over-the-top most of the time. I carry a knife in stainless because it was the least expensive knife I could find. Quantity has a quality of its own.

I prefer a straight edge to a serrated edge.


And even though it is heresy in some circles, much of my finer cutting work (like grafting) is done with a work knife with disposable blades.


  1. I agree about your assessment of knives. I did ruin a folding knife years ago because I ground it back for a narrower profile and for into non tempered steel. My one son who is a plumber, carries a folding version of your replaceable blade work knife. He used it for everything, even skinning and quartering a moose!

  2. I carry one of those "box cutter" knives EDC for self defense and utility uses. Not much of a weapon ? Well it is VERY sharp and cuts nearly an inch deep, and if I ever need to use it offensively, I can throw it away and only be out a couple of bucks. Think outside the box.

    1. Those Frost knives he linked to would be great in that application. Stab and scoot, leaving the knife behind in the dirtbag.

  3. Oddly, I can resharpen one of those box cutters faster than I can change the blade. I use one of those DMT sharpeners. Couple passes, then keep going.

  4. I made a living in a trade which meant using a knife every day. The Stanley 99 as pictured was an important tool in my kit. I too resharpened the disposable blades a couple times before tossing them, partly as a matter of convenience and partly out of economics.