Up to 20 tons of string tension is being exerted within a piano at all times. It is the function of the cast-iron plate to accomodate the extraordinary force and provide strength and stability throughout the life of the piano.
Since 1998, Steinway & Sons operates its own foundry in the US solely to produce the elemental, integral cast-iron plate to our exacting specifications. Our foundry forges the bell-quality plate with a new No-Bake Process implemented just five years ago, which permits a single-use high-strength mold that creates more precise and consistent casting.
We have also added a revolutionary thermal reclaiming process. Additionally, new machinery enables greater precision for the milling of the plate (up to 0.008 of an inch). Finally, our metallurgy lab has been modernised to further optimise the hardness and strength of the casting, all but eliminating potential deformations or cracks hat could occur once the plate is strung.