Nubatama Synthetic Waterstones

Out of production and sourced directly from the Ken Schwartz Estate, Nubatama stones are rare, small-batch Japanese abrasives built for maximum cutting speed on everything from classic carbon to high-alloy steels.

Mix and match across lines—you aren't locked into one. Each series fills a distinct role, allowing you to build a custom progression tailored to your steel and workflow:

• Bamboo (Splash & Go): Hard, low-porosity, and fast-cutting. No soaking required—ideal for rapid stock removal and low-maintenance edge maintenance.

• Ume (Tactile & Soaking): Softer, porous matrix requiring a brief soak. Releases a rich, cushioned slurry for maximum tactile feedback and smooth bevel work.

• Platinum (Ultra-Hard): Maximum density and wear resistance. Engineered specifically to cut high-vanadium super-steels without glazing or dishing.