Tungsten Carbide Ball

Cemented Tungsten Carbide is an incredible material. It was originally developed for use as a cutting tool, in machine tools applications, where it still finds wide use today.
It is extremely hard at 91 HRA which is equivalent to 1500 Vickers 30. This material is very wear resistant, with some abrasion tests showing it at 30 times hard steel. It has good long-term dimensional stability, which makes a good material for gage applications.
Cemented Tungsten Carbide is extremely stiff, with a Young's modulus of elasticity of 98,000,000 pounds per square inch, compared with steel at 30,000,000 PSI. This high stiffness makes cemented tungsten carbide balls a good choice for ball-sizing and they provide premier results as components of kinematic couplings.
Its good performance at temperatures up to 800 degree Fahrenheit ( 427 centigrade ) make it a good choice in high temperature applications.
It has good corrosive resistance in many environments.
The material has a very low rate of thermal expansion, at 2 microinches per inch per degree Fahrenheit (4.9 X 10-4 per degree C). Steel is 6.4 and aluminum is 12 microinches per inch per degree Fahrenheit.
One of the very important features of this material is that it is electrically conductive, with a resistivity of two micro ohms per centimeter. This conductivity sets it apart from other hard stiff materials, such as ceramics and sapphire, because it allows it to be machined into complex forms by the Electrical Discharge Machining (EDM) process. Cemented Tungsten Carbide can be ground and lapped using diamond grit. The material is slightly magnetic. Small diameter balls can be picked up with a magnet. Cemented Tungsten Carbide is very heavy, with a density of .54 pounds per cubic inch or 15 grams per cubic centimeter.
Cemented Tungsten Carbide is neither a metal nor is it a ceramic. It is a cermetal although this isn't a widely used term. This is a combination of a large percentage of Tungsten Carbide ceramic particles bonded together by a small percentage of a metallic binder, to form a solid mass.