Stability and balance – the Iron Plate
The Kelly Foundry in Springfield (Ohio, USA) produces the 180-kilogram cast-iron plates for Steinway New York and Hamburg. They are produced by a traditional moulding process using synthetic sand. The cast-iron plate stabilizes the overall structure of the grand piano and absorbs tension from the strings.
The iron plate itself is the only part of the grand piano that does not resonate. Its weight and the high carbon content of the grey cast iron prevents the strings from losing vibration energy. Steinway craftsmen work on the iron plate with a drill and milling machine and then sand and bronze it by hand. The final step in this phase is painting the incorporated Steinway & Sons lettering by hand.
Discover how a Steinway is manufactured
Visit us at the different stages of the creation process
Watch the full factory tour on YouTube.