D2 tool steel just keeps cutting. It’s been around a long time and enjoys a solid reputation among custom and factory knifemakers and knife users. As with many high-performance steels, it experiences a range of highs and lows in popularity, and at the moment seems to be enjoying a high.
A favorite steel of such long-time knifemakers as BLADE Magazine Cutlery Hall-Of-Fame© member Wayne Goddard and Bob Dozier—the latter has been called “Dr. D2” on more than one occasion—D2 is considered a “borderline stainless steel” because it contains 11.5 percent chromium. To be classified as stainless, a steel must have at least 12 percent chromium. (Note: stainless simply means a steel resists corrosion. It does not mean it is stain proof.) According to Scott Devanna of SB Specialty Metals, D2 also has a very high carbon content—1.5 percent—which lowers corrosion resistance because the carbon “grabs” a lot of D2’s chromium to form chromium carbides. The chromium carbides are good for improving wear resistance—improved wear resistance enhances edge holding—but they tie up chromium so it is not as “free,” and thus reduce corrosion resistance. Free chromium forms a chromium oxide layer at the surface, and the layer makes a steel corrosion resistant. This helps explain why D2 is not stainless.
While D2 may not be stainless, it remains a top performer due in no small part to its high wear resistance/edge-holding ability. “It will hold an edge for a very long time before it will go dull,” says Paul Tsujimoto, director of engineering at Ontario Knife Co. Combined with its relatively inexpensive price, this makes D2 a favorite of manufacturers and custom makers alike. “For us, it’s the perfect combination of performance and an affordable price,” notes Dietmar Pohl of Pohl Force Knives. Agrees Devanna, “It’s the best bang for the buck because it’s priced reasonably and works well.”
On the down side, D2’s ample wear resistance also means it is difficult to sharpen. However, a diamond abrasive sharpener should do the trick. Also, the steel’s impact toughness suffers in comparison to some other steels, so D2 is not the best choice for a blade used for chopping and other impact-type cutting chores. And, since it’s not a true stainless, you should wipe it down after use to help keep corrosion to a minimum.
Nonetheless, D2 is an outstanding choice for a hard-use knife and remains popular among custom knifemakers and manufacturers, and knife users as well.