Böhler M398 is one of the newest and most advanced stainless powder metallurgy steels available to knife makers today, but its origins can be traced back through decades of metallurgical innovation rather than a single breakthrough. The alloy is the product of Böhler’s long-standing effort to push the limits of wear-resistant stainless tool steels, a pursuit that began well before M398 itself existed. Founded in Vienna, Austria, in 1870, Böhler established a reputation for producing premium specialty steels for some of the world's most demanding industries. Over the following century, the company became known not only for its high-quality alloys, but also for continually refining steelmaking processes to solve increasingly difficult engineering problems. By the late twentieth century, Böhler had become one of the pioneers of powder metallurgy, allowing its engineers to produce steels with alloy compositions that conventional ingot casting simply could not achieve.

- Bohler was founded in Vienna, Austria, in 1870

The changes Böhler made were deliberate rather than dramatic. Carbon content increased from 1.9 percent in M390 to 2.7 percent, while vanadium rose from roughly 4 percent to an impressive 7.2 percent. Chromium remained at 20 percent to preserve the alloy's stainless characteristics, while molybdenum, tungsten, manganese, and silicon rounded out the composition. Together, these adjustments created an alloy capable of forming a substantially greater volume of extremely hard vanadium carbides, giving M398 significantly greater resistance to abrasive wear than its predecessor.

Like every member of the MICROCLEAN family, M398 is produced using powder metallurgy. Instead of allowing molten steel to solidify into large ingots, the steel is atomized into microscopic powder particles that cool almost instantly before being consolidated into fully dense billets under tremendous heat and pressure. This manufacturing process creates an exceptionally fine and uniform carbide distribution throughout the steel, eliminating many of the segregation issues associated with conventional steelmaking. The result is an alloy capable of achieving levels of wear resistance and consistency that would be extremely difficult, if not impossible, to produce using traditional methods.

Composition

Carbon - 2.7

Chromium - 20%

Molybdenum - 1%

Tungsten - 0.7%

Vanadium - 7.2%

Manganese - 0.5%

Silicon - 0.5%

As manufacturers became more familiar with processing the alloy, M398 gradually expanded beyond the custom knife market into premium production models. Companies including Spyderco, LionSteel, Fox Knives, Vosteed, Bestech, Poikilo, and several boutique makers have incorporated M398 into limited-production and flagship models, typically positioning it as a premium option for enthusiasts seeking maximum edge retention. While it remains considerably less common than other steels, its growing availability showcases the increasing confidence in the alloy's performance and the industry's ability to machine and heat treat such a highly alloyed steel.

More than a century after Böhler began producing specialty steels in Austria, M398 stands as the latest chapter in the company's long history of metallurgical innovation. It demonstrates how advances in powder metallurgy continue to expand what is possible in blade steel design, pushing performance into territory that would have seemed unattainable only a few decades ago. Whether it remains a niche alloy or becomes more widely adopted, M398 has already secured its place among the most technically advanced stainless steels ever developed for cutting tools.

Spyderco/LionSteel SpyMyto