By David E. Petzal

Those of you who follow my rantings and ravings are aware of my creepy—bordering on unnatural—fondness for Diamond Blade knives. I think they’re about the best working knives you can buy, both because of their excellent design, and because they will stay sharper longer than anything else that cuts. This is not based on gutting one deer; it’s based on the 100 yards of ½-inch manila rope which I reduced to nothing, half an inch at a time, over the course of several years, slicing away with all sorts of knives to see which kept their bite longest. A number of them did extremely well, but none could match a Diamond Blade.
If you’re new to the name, Diamond Blades are made of D2 steel, which is common in the knife biz, but the edges are subjected to a unique process called Friction Forging, which subjects the metal to great heat and immense pressure. (It’s an adaptation of the technique by which submarine hulls are joined together.) This results in a blade whose edge is so hard that its Rockwell number is off the chart (65 to 68 on the C scale; 62 is regarded as absolute max on conventionally tempered blades) while the spine is Rc 42-45, about as hard as a rifle receiver.
The result is the same as Japanese swordsmiths achieved with katana blades—an extremely sharp, durable edge, and a nearly unbreakable blade. I once watched a Diamond Blade bent double in a vise, then bent straight again, and it didn’t care much if at all.