Fallkniven FS4 Flipstone Ceramic Diamond Pocket Sharpener

The Fallkniven FS4 Flipstone is a pocket sharpener that works on a completely different level than the ceramic rods and pull-through gadgets most people carry in the field. The double-sided stone combines a 25 micron diamond surface coated in Titanium Alumina Nitride for fast edge reshaping with a 1 micron synthetic sapphire ceramic surface for finishing to near mirror polish. Diamond rates 10 on the Mohs hardness scale, ceramic rates 8, which means this sharpener will cut and refine even the hardest modern powder metallurgy steels without loading up or losing flatness over time.

The spring-loaded Zytel handle deploys the 3 inch stone at the press of a button and locks it open for use, then folds back closed for safe pocket carry. Both surfaces are used completely dry with no oil or water required, and cleaning is as simple as soap and water when the stone loads up with swarf. The stone actually improves slightly with use as it smooths in, and the flat surface geometry keeps your sharpening angle consistent in a way that rounded or tapered rods cannot. At 4.375 inches closed it carries like a pocket knife and weighs almost nothing. Made in Sweden by Fallkniven, one of the most respected names in high-end Scandinavian cutlery.

Best for: Field sharpening, everyday carry, high-end knife maintenance, anyone running premium powder steels that conventional sharpeners struggle with, or anyone who wants a serious compact sharpener from one of the best makers in the world.