While it is technically possible to use a knife sharpener to sharpen a katana, it is generally not recommended. Knife sharpeners, especially those designed for kitchen knives or handheld sharpeners, may not be suitable for the unique shape, size, and curvature of a katana blade.

Katana blades have a distinct shape with a curved edge and a single bevel. They require specific sharpening techniques and tools to maintain their geometry and cutting performance. Using a knife sharpener that is not specifically designed for katana blades can risk damaging the blade or altering its shape.

To properly sharpen a katana, it is advisable to use traditional sharpening methods such as whetstones or specialized katana sharpening tools. These tools allow for precise control over the sharpening angle and maintain the integrity of the blade's geometry.

If you are unsure about sharpening your katana yourself, it is recommended to seek the assistance of an experienced professional or a knowledgeable swordsmith who can ensure the proper sharpening and preservation of your katana. They will have the expertise and appropriate tools to sharpen the blade effectively and safely.