Composites are strong, light-weight materials widely used in aviation and sports. Much like an alloy, a composite is made from two or more different materials. The resulting material benefits from the properties of both. Composite materials have important advantages over wood. Bicycles, tennis rackets, golf clubs, and now action parts have all benefited from modern materials.
Strength. Strength and rigidity are very important in an action part. Composite parts use Nylon and similar compounds as a base resin and a long fiber (Carbon) for stiffness. Maple, commonly used in piano actions, has an average strength of around 2,500 psi. Composite parts have a tensile strength of aprox. 31,000 psi - over ten times as strong.
Uniformity. Composites are uniform in strength and mass. Unlike wood, they possess equal strength in all three axes. This produces parts consistent in strength and mass while allowing designs not possible in wood.
Design. One manufacturer has designed a system of parts with the ability to easily correct action geometry and the flexibility to adapt to a wide variety of pianos.
Accuracy. Because of the accuracy of injection molding, manufacturers can make a more accurate part than can be achieved by conventional machining.