Harp--aka Plate

Rawlins & Co. harps are fabricated in the conventional sand-cast method.

Look at any vintage piano of note: Steinway, Mason & Hamlin, Chickering...or other fine pianos all contain a sand-cast harp.

Sand-cast harps have stood the test of time.

The second way a plate is produced is by vacuum casting. Vacuum-cast harps require less hand-finishing before being installed in a piano. This seemingly more efficient process may enable the timbre of the metal to change.

There are two different ways to manufacture a plate. One, the traditional way, is called a sand-cast.  A sand-casting allows the bell quality cast iron to harden naturally.