Since we made our first knife nearly 40 years ago, Spyderco has earned an enviable reputation as one of the industry leaders in the use of new and exotic blade steels. In addition to large-scale innovation—like the rustproof H-1
® used in our Salt Series™—we also enjoy offering specialized, high-performance steels in select products. This allows customers with an advanced appreciation of cutlery steels to experience the performance nuances of exotic blade materials.
With this spirit in mind, Spyderco is proud to introduce several knives featuring K390 MICROCLEAN
® steel. Manufactured by Böhler-Uddeholm, K390 is an advanced cold work tool steel produced by the particle

metallurgy process. Its sophisticated alloy mix was specifically developed to provide the extreme wear resistance and high compressive strength needed in industrial cutting, blanking, and punching operations. Remarkably, its exceptionally fine, homogeneous microstructure also makes it readily machinable and easy to heat treat. As a blade steel, these qualities translate to outstanding edge retention and excellent toughness. In fact, the FAQ page on Böhler-Uddeholm’s web site openly states “Our best tool steel for edge retention and toughness is Bohler K390...” When a steel manufacturer of their status makes a statement like that, it says a lot.
K390's unique alloy composition includes the following elements: Carbon - 2.47%, Chromium - 4.20%, Molybdenum - 3.80%, Manganese - 0.40%, Vanadium - 9.00%, Tungsten - 1.00%, Cobalt - 2.00%, and Silicon - 0.55%. Note that its relatively modest chromium content is well below the 13% threshold for a stainless steel. As such, it is a true tool steel and must be properly maintained to prevent corrosion.

Spyderco’s first offering in K390 was our MT17 Mule Team knife. In the knife industry, a “mule” is a sample knife used for performance testing. Based on our own extensive in-house tests and feedback from devoted Mule Team fans, we were very excited about K390’s performance. We therefore decided to use it in a special Sprint Run version of the Urban™ Lightweight SLIPIT™. Housed in a distinctive gray fiberglass-reinforced-nylon (FRN) handle, the K390 blade supercharges the cutting performance of the Urban and makes it one of the most capable non-locking cutting tools available.
If you’ve taken the time to review Spyderco’s 2017 Product Guide, you may have noticed another K390-bladed knife on the horizon—the Police™ 4. The latest evolution of our venerable Police Model, this fourth-generation design will feature refined ergonomics and a voracious full-flat-ground K390 blade. It is slated for release later this year.
Pushing the envelope of performance is a Spyderco obsession. We are proud to offer elite cutlery steels like K390 to our customers and look forward to your feedback on their real-world performance.