THE SCIENCE BEHIND THE STEEL
Wikipedia describes tool steel as a “variety of carbon and alloy steels that are particularly well-suited to be made into tools”. The Benchmade website describes D2 as “An air-hardened tool steel, which offers good corrosion resistance and excellent mileage in wear resistance. A good choice for hard use applications.” The Spyderco website describes D2 as a mix of the following, Carbon (1.55), Chromium (11.50), Molybdenum (.90), Manganese (.35), Silicon (.45), and Vanadium (.80). Wiki Answers describes D2 as a steel that is “difficult…to machine and requires a special wheel for surface grinding….It also hardly moves during the treatment process….” It also mentions that since D2 has a high chromium content, that it does have some stainless steel properties although it cannot and is not classified as a stainless steel.
WHY DO I NEED A D2 KNIFE BLADE?
In layman’s terms, what does all of this technical info mean. What it means is that D2 is an incredibly hard steel that is specifically designed for high impact and heavy use tools. Since it is so hard, it works fantastic for knife blades that are going to see heavy use. Think heavy wilderness, desert sand, high mountains, or any other inhospitable and wild place. D2 works well in these environments because it is built for hard use and heavy applications.
For instance, the new 2750 Adamas Auto AXIS knives use D2. Because these knives are built as heavy duty, all purpose, automatic combat knives that could potentially see heavy use in very hostile conditions, the choice of D2 steel makes sense. It means the blade will stand up to extensive use without dulling quickly and will offer some corrosion resistance–which is critical for a heavy duty knife. Many of the Benchmade Bone Collector knives also feature D2 tool steel. Although the use of D2 tool steel increases the cost of the knife–it is well worth it to the knife user who relies on his knife as a tool that will perform when it counts most.
A knife with a D2 Tool Steel blade is going to do the following for you: it will maintain a good edge, it will stand up to heavy duty as well as hard use, it will provide some corrosion resistance.