Diamond Tooling

The strongest tools, made from the earth’s hardest mineral

Nanami Kaito | Nissin Diamond

Diamond Tooling

A diamond tool is a cutting tool with diamond grains fixed on the functional part of the tool by methods such as brazing. There are numerous kinds of diamond tools available in the market and they are categorized by manufacturing methods and usage. Diamond is made of the hardest mineral on earth with outstanding hardness, strength, and chemical stability (at temperatures of 600 K or less) and a friction coefficient of 0.1 or less. These properties result in extremely high accuracy compared to cutting tools made from other materials. Moreover, diamond tools can be repolished with sharpened cutting edges, making them an environmentally friendly tool option.

Nissin Diamond offers synthetic single-crystal diamond inserts and polycrystalline diamond (PCD) cutting tools in a wide range of variations.

Diamond tools are ideal for the processing of non-metallic materials and non-ferrous metals due to their excellent hardness and diffusion of heat properties. Diamond tools are commonly used in industries including IT, home appliance, construction machinery, automotive, aerospace, medical equipment and more. In recent years, diamond tools are especially in demand for the processing of optical components and metal molds that are small, require ultra-precision and mirror surface finish.

Diamond Tooling by Nissin Diamond

Nissin Diamond Co., Ltd. is a cutting tool manufacturer based in Takashima, Shiga, Japan. Nissin Diamond has been active in the development, production and sales of diamond cutting tools since the company’s founding in 1968. In September 2006, Nissin Diamond became a consolidated company of OSG Corporation.

Nissin Diamond’s operators pose for a photograph at its factory. Currently employing approximately 45 employees, Nissin Diamond’s headquarters and its Aiba Factory are located in Takashima in the northwestern part of Lake Biwa, Japan’s largest freshwater lake.

Nissin Diamond specializes in the production and sales of natural diamond cutting tools, synthetic single-crystal diamond cutting tools, polycrystalline diamond (PCD) cutting tools, and polycrystalline cubic boron nitride (PCBN) cutting tools.

Natural Diamond Cutting Tools

Natural diamonds are formed in the earth’s mantle when carbon crystallizes over the course of billions of years at extremely high pressure and temperatures. Natural diamond provides the best sharpness for cutting blades. As a natural product, the quality of these diamonds can vary considerably. However, the unparalleled sharpness they provide as cutting blades is indispensable in the ultra-precision machining of items such as molds for aspherical lenses.

Natural diamond cutting tools are primarily used for finishing in aluminum applications. The diamond can be brazed to an existing indexable insert or a carbide tool body. Natural diamond cutting tools leverage the characteristics of diamond to improve the accuracy of work pieces used in micro and ultra-precision machining.

Synthetic Single-crystal Diamond Cutting Tools

Synthetic diamond is manufactured by crystallizing carbon-based components under strict quality control at high temperature and high pressure conditions. Since this substance is created by the work of humans, supply is more stable than natural diamond. In addition, although synthetic diamond has the same chemical structure as natural diamond, it is a stable crystal with few impurities, defects, and distortion, enabling consistent cutting performance.

Surface roughness comparison in aluminum alloy.

The image on the left is a workpiece machined by a PCD tool with a surface roughness of Ra 300 n. The image on the right is a workpiece machined by Nissin Diamond’s synthetic single crystal diamond cutting tool with a surface roughness of Ra 50 n. The workpiece by the single-crystal diamond cutting tool exhibits a shiny surface finish, whereas the surface by the PCD tool measures six times higher roughness. Nissin Diamond’s synthetic single crystal diamond cutting tools are effective for machining that requires stable quality and long tool life, such as highly transparent resin machining, optical parts, and precision machining of automobile-related parts.

Natural and synthetic single crystal diamond cutting tools are manufactured by special brazing and polishing techniques. They are effective for machining that requires stable quality and tool life, such as highly transparent resin machining, optical parts, and precision machining of automobile-related parts.

Polycrystalline Diamond (PCD) Cutting Tools

Similar to synthetic single-crystal diamond, polycrystalline diamond (PCD) is another type of diamond. PCD cutting tools are most commonly used in non-ferrous and non-metallic materials. As performance in automotive component improves, better aluminum alloys and improved tool performance are also required. PCD tools provide consistent precision and longer tool life than that of carbide tools. In addition to having excellent durability, PCD cutting tools improve the quality of parts and significantly reduce costs across the entire production cycle with faster cutting speed.

Polycrystalline Cubic Boron Nitride (PCBN) Cutting Tools

Polycrystalline cubic boron nitride (PCBN) is an artificial mineral consisting of nitrogen and boron that does not exist in nature. CBN powder is made by treating hexagonal boron nitride (HBN) at high temperature and pressure. The PCBN sintered body is baked at high temperature and high pressure together with binders such as cobalt and TiN. PCBN cutting tools are suitable for machining iron-based metal materials such as hardened steel, cast iron, and sintered metal, which are difficult to machine with diamond tools. PCBN tools also offer higher speed, precision and tool life than carbide tools.

PCBN does not oxidize in the atmosphere up to 1300-celcius whereas diamond begins to graphitize at 700-celcius. Due to this characteristic, PCBN does not react with iron. PCBN is second only to diamond in terms of hardness and thermal conductivity, making it a great fit for machining alloy steel and cast iron of 45 HRC and above.

Diamond and PCBN tools can provide exceptional performance, precision and long tool life in many work applications. Nissin Diamond will strive to further enhance its ability in terms of cost, delivery time, quality, and actively promote the development of new proprietary technologies to respond to evolving market needs.

For more information on Nissin Diamond


About Nissin Diamond

Nissin Diamond Co., Ltd. is a cutting tool manufacturer based in Takashima, Shiga Prefecture, Japan. Nissin Diamond has been active in the development, production and sales of diamond cutting tools since the company’s founding in 1968.

Nobuaki Kamiya, CEO of Nissin Diamond, poses for a photograph at the company office in Takashima, Shiga, Japan.

Nissin Diamond specializes in the production and sales of natural diamond cutting tools, synthetic single-crystal diamond cutting tools, polycrystalline diamond (PCD) cutting tools, and polycrystalline cubic boron nitride (PCBN) cutting tools.

Nissin Diamond’s operator prepare for the machining of new products.

Nissin Diamond’s products are used in a wide variety of industries including IT, home appliance, construction machinery, automotive, aerospace, medical equipment and more. Many items used in daily life are machined using Nissin Diamond tools.

Nanami Kaito, Nissin Diamond Customer Service Representative, poses for a photograph at the company factory in Takashima, Shiga, Japan.

In September 2006, Nissin Diamond became a consolidated company of OSG Corporation. Currently employing approximately 45 employees, Nissin Diamond’s headquarters and its Aiba Factory are located in Takashima in the northwestern part of Lake Biwa, Japan’s largest freshwater lake.


Official Brand Mascot Daiyan

Daiyan is Nissin Diamond’s official brand mascot. It is a fictional cutting tool character based on the imagery of a diamond cutting tool, which is a core product of Nissin Diamond since its founding in 1968. The friendly diamond cutting tool character Daiyan serves as Nissin Diamond’s brand ambassador in the promotion of the company, the manufacturing industry, and local communities.


The OSG Group

OSG Corporation has individual production facilities for designated tooling lines including taps, HSS drills and end mills, carbide drills and end mills, rolling dies and gauges, tool coating, and machine tools. In addition to OSG’s own product lineup, OSG also fulfills customer needs with its domestic group companies specialized in their respective fields. Each domestic group company manufacturers and sells the products they specialize in. Together, they offer a broad lineup of products and services, including the manufacturing of carbide materials and cutting tools, coating and regrinding services, as well as sales of machinery. They also offer various custom services, ensuring that each and every client will always receive products that suit their desired processing environment.

Internationally, OSG has a global network of over 65 business offices in 33 countries, which provides its production sites with accurate feedback about user needs so that the company can quickly design, develop, manufacture and deliver products that precisely meets those needs.

For more information on OSG’s domestic group companies