It’s a Steel: Random Facts About Knife Blades

ka-bar
Ka-Bar Knives uses 1095 steel for its blades.Ka-Bar

What the hell, since we're done knife handles, we might as well do blades. According to the A.G. Russell steel charts, there are something like 84 knife steels that you can choose from, and I'm damned if I'm going to run down them one by one. In case you don't know who A.G. Russell is, he is the fellow who is as responsible as any one person for the custom knife boom which began in the late 1960s and continues to this day, and for the subsequent renaissance of the American cutlery industry.

A.G. is 83, and is still selling knives and promoting the craft of the cutler. His steel charts (one for stainless, one for non-stainless) was first posted in 1998, and is the most complete and comprehensible guide to the subject I know of. Agrussell.com/chart. The other thing I should mention is that A.G., who is an Arkansan, detests the Clintons more than anyone I know, and I know a great many people who detest the Clintons a whole lot.

So, herewith some random facts.

There’s no such thing as true stainless steel. An alloy that’s absolutely proof against rust would have to contain so much chromium that it would be useless as a knife. The most popular near-stainless steels are 440A, 440B, and 440C, and I dislike them all. On the one hand, it’s almost impossible to get them to rust or stain. On the other, you can’t get a blade made from any of the three really sharp.

There are a fair number of near-stainless steels that take a very good edge and keep it. Not in order of preference they are: 154CM, ATS-34, AUS-6, AUS-8, BG-42, the CPM stainless series, Sandvik 12C27, and Krupp 4116. Plus, whatever stainless steels Morakniv and Helle use in their blades.

However, I've come to prefer tool steel because it does a number of things that the others don't. First, because it will rust and stain, it will gradually blue over the years. This is rather like a fine wood gunstock aging and darkening, and is very handsome. Look at a well-cared-for butcher knife some time to see what this is like. Second, a skilled smith can forge tool steel to a differential heat treat—a very hard edge and a softer, more flexible spine, which gives you both a superior edge and considerable blade strength. Japanese swordsmiths make katanas and wakazashis this way, and accentuate the temper line, which is called a hamon. Lamont Coombs has made a couple of hunting knives for me that incorporate a hamon, and it is cool to the nth degree.

Tool steel blades can be made sharper than anything else, and while they don’t hold that edge while you field-dress three moose and a brown bear that’s been rolling in mud, they can be re-sharpened with extreme ease.

My tool-steel favorites are, not in order: 0-1, which is the steel Randall has used lo these many years.

1095, a very simple alloy which has been around forever, has been used in a great many inexpensive knives (Ka-Bars are 1095) but still furnishes the blades for some very costly knives as well.

5160, which is used to make automobile leaf springs, and which the great smith Bill Moran considered the best of the knife steels. I’m told it’s now getting hard to find.

D-2, which contains a lot of chromium for a tool steel, and is used to make forming dies. For a hard-use knife, this is probably numero uno. It's rust-resistant, although it will stain, very tough, takes a first-class edge and holds that edge nearly forever. For a survival or tactical knife, you can't do better. DiamondBlade Knives uses D-2 for its blades, subjects it to their unique zone tempering process, and the result will hold an edge forever.

And remember that steel is only one of three factors that determines how well a knife cuts. The second is what the smiths call geometry—how the blade is shaped in cross section. Put in English, this means that a knife with a thick edge will not cut, no matter what you do to it. And, whether the blade is heat-treated in an electric furnace or forged by eye in a charcoal fire, the smith has got to know what he’s doing. Too soft and it won’t cut. Too hard and it will break.

Now, I’m going off to sharpen a knife.