Naniwa

Naniwa Abrasive Mfg. Co., Ltd. is a renowned Japanese manufacturer of sharpening stones founded in 1941, with over 80 years of experience in the abrasive materials industry. The company has gained a leading position thanks to years of refining production processes and applying the latest technologies, earning recognition among both amateurs and professionals engaged in self-sharpening knives.

History and production philosophy

Naniwa was created with the vision of producing stones that would best "collect steel," manufacturing them using the most advanced technologies. For decades, the company has consistently pursued this philosophy, which allowed it to stand out from the competition. In 2009, Naniwa obtained ISO 9001 certification, confirming the high quality of products and services, and ISO 14001, demonstrating ecological responsibility and commitment to sustainable development.

Although Naniwa is best known for producing sharpening stones, its offer includes a much wider range of abrasive products. The company supplies materials for almost all industrial sectors, including cutting and grinding in construction, diamond and abrasive discs for edge sharpening, as well as abrasive powders used in the production of semiconductors and precision devices.

Technical characteristics

Naniwa stones are characterized by an exceptional ability to maintain flatness even after prolonged use, making the sharpening process more precise and predictable. The company mainly uses aluminum oxide (corundum) as the abrasive material, combining it with various bonding systems depending on the intended use of a particular series.

Bonding systems

Naniwa employs different bonding technologies tailored to the specifics of individual series. Resin bonding is characterized by a good balance between durability and sharpening effectiveness, while magnesium bonding provides greater hardness and sharpening precision. The bonding material produced in-house by Naniwa softens under water during grinding, which ensures that the cutting edge of the blade is constantly refreshed by new abrasive grains.

Available product series

Naniwa Advanced

A versatile series of sharpening stones intended for both amateurs and semi-professionals. It uses aluminum oxide as the abrasive material and resin bonding, providing a good balance between durability and sharpening effectiveness. Stones are available in two thicknesses (10 mm and 20 mm) and require a short soaking before use. Thanks to a wide range of grits from #220 to #12,000, they are suitable for both edge repair and blade finishing.

Naniwa Chosera Pro

They use aluminum oxide as the abrasive material and magnesium bonding, which ensures hardness and sharpening precision. Due to their high performance, they are ideal for kitchen knives, woodworking tools, and precision blades. These stones do not require long soaking before use, offer exceptional smoothness of operation, and even abrasion.

Naniwa Multi Stone

Double-sided series combining two grits in one stone, such as the popular 1000/3000 combination. The first side (1000) is suitable for regular, basic sharpening, while the second with a 3000 grit is intended for finishing and polishing the blade. They feature a relatively hard binder compared to other series, which translates into long durability.

Naniwa Super Stone

A series starting from grit #220, which allows quick repair of even the most neglected knife. Before use, the stone should be soaked in water for about 2 minutes. At the 1000-3000 level, a truly practical, working cutting edge can be achieved.

Compatibility and application

Naniwa stones work well with a wide range of steels - from high-carbon non-alloy steels typical for Japanese tools to alloy steels used in the production of European tools. Due to their size and shape, larger blocks are suitable for sharpening chisels of any width, plane blades, kitchen knives, and can work with all typical sharpening guides.

Usage and maintenance

Most Naniwa stones require a short soaking in water before use - usually about 2-10 minutes depending on the series. During sharpening, an active abrasive slurry forms, which significantly improves the effectiveness of the process. The stones are characterized by stability during work and resistance to uneven wear.

Advantages over the competition

Naniwa stands out on the market primarily due to the use of the latest production technologies and consistent pursuit of optimizing the "steel collecting" process. The company offers an excellent price-to-performance ratio, especially in series intended for those starting their adventure with water stones. ISO certification and over 80 years of experience guarantee quality stability and product reliability in long-term use.