Normally, diamonds (synthetic or natural) for industrial uses are small-size grains, and are difficult to be directly used as tools. They are usually fixed on the valid working parts of a tool via some kinds of bond materials or by some other special means to form a kind of tool, which has a certain shape, strength and uses. These tools are normally called diamond tools.

There are various kinds of diamond tools, and because of their superb sharpness, they have been widely applied in many domains, including construction, electronic information, geological mining, medical devices, etc. According to their bond types, manufacture methods and uses, diamond tools can be categorized to the following types:

1) Metal Bonded Diamond Tools: They are made via the steps of mixing diamond grains with metal powder (e.g., Cu, Sn, Fe) evenly, applying powder metallurgy methods to press the mixtures to some shapes and sinter them, and mechanical processing. This type diamond tools are the most often sighted. They include the common diamond blades, diamond grinding cup wheels, diamond core bits, etc.

2) Resin Bonded Diamond Tools: They are made via the steps of mixing diamond grains with resin powder and some proper fillers (e.g., copper powder), cold pressing or hot pressing them to some shapes, curing, and mechanical processing. This type diamond tools have characteristics of good elasticity, good impact tolerance, good self-sharpening capability, and high grinding efficiency. An example of this type diamond tools is diamond polishing pads.

3) Plated Diamond Tools: They can be made by using electroplating methods to plate the tool’s surface with one or several metal layers, in which diamond grains are distributed evenly. Another method is using CVD (Chemical Vapor Deposition) method to deposit a layer of dense polycrystalline diamonds on the tool’s surface. Plated diamond tools include some diamond cutting tools, drilling tools, etc. They have characteristics of high efficiency, long life and high grinding precision.

4) Ceramic Bonded Diamond Tools: They are made via the steps of mixing diamond grains with glass and ceramic powder, pressing the mixtures to shapes, sintering, dressing, and sharpening. This type diamond tools include some diamond grinding tools. Their characteristics are: good chemical stability, small elastic deformation, high brittleness, etc.

5) Polycrystalline Diamond (PCD): They are normally made by sintering many micro-size single diamond crystals in high temperature and high pressure. The crystals in PCD are arranged disorderly, so the hardness and wear resistance of PCD in all directions are almost the same. PCD also has good fracture toughness and good thermal stability. It can be applied in geological drill bits, machining tools, etc.

6) Polycrystalline Diamond Composite or Compacts (PDC): They are made by combining some layers of polycrystalline diamonds (PCD) with a layer of cemented carbide liner in high temperature and high pressure. PDC has the advantages of diamond’s high wear resistance and carbide’s good toughness.