How Pianos Are Made

In the early part of the 20th century, there were more than 300 piano makers in the U.S. Today there are about 15. Most pianos today are made in Japan.

The piano is a stringed instrument with more than 2,500 parts. How all those parts go together makes an interesting story – about how pianos are made.

The Manufacturing Process

In modern piano factories, workers at each station (or step) do the same job repeatedly and the process is very much like an assembly line.

Lumber Mill

It all starts at the mill where special logs are selected, stacked and slowly seasoned over time.

Eventually the logs are sawn, trimmed, planed and processed into boards.

Factory Kiln

The boards arrive at the piano factory where climate controlled kilns heat and treat the lumber, assuring proper moisture content.

Some boards are used to produce the furniture-like case. Others have a musical job to do.

Soundboard

Selected boards are edge-glued to form the soundboard, which acts as an amplifier for the sound produced by the strings. After drying and seasoning, the soundboard is trimmed to proper size.

The wood fibers of the soundboard are stretched by bending the soundboard or “crowning.”

Ribs are glued on the backside following which the soundboard is mounted on the wood caseorrim.

Bridges & Pinblock

Two bridges are attached to the finished soundboard and notched, a process that allows the strings to be seated properly.

The pinblock, on the front of the finished soundboard holds the tuning pins in place as well as the two notched bridges.

Soundboards are normally attached to the back frame. Some piano makes allow part of the soundboard to “float” and it is not attached to the frame. This produces a richer sound.

Cast Iron Plate

The 220 strings found on a typical piano exert tremendous tension on the plate or cast iron frame when tuned.

The plate is mounted to the back frame above the soundboard. Holes for the tuning pins are carefully drilled into the soundboard pinblock, guided by holes in the plate.

Pins are carefully driven in to an exact height. At this point the entire backframe assembly including the soundboard, cast iron plate and pinblock with pins installed moves to the stringing department.

Stringing

Strings are attached by a skilled “stringer.” Each string end is wound around the top of the tuning pin exactly two and one-half turns.

After attaching, the strings are imprecisely tuned in a process called “chip tuning.” The purpose is not to get the piano perfectly in tune but to bring the piano gradually up to proper pitch.

The completed backframe, with strings attached sits for a period of time to stabilize before another series of more precise tunings takes place.

Case

While all this is going on, in another part of the factory the case is under construction. The case is made like furniture with parts cut, trimmed, milled and sanded until they are assembled into the specific case for that piano.

Following construction, the case is finished with varnish, wax or even paint, depending on the model and desired look.

At this point, the back frame is installed in the case.

Keys and Hammers

In another part of the factory the piano action, consisting of the keys, hammers and many other small parts are being assembled.

The action is the most complex part of a piano and requires skilled craftsman to produce the various components.

Eventually the keys, hammers and other parts are all assembled and balanced — sometimes using lead weights.

The action is installed on the piano first, followed by the keys.

Regulation & Tuning

Following installation the action goes through multiple adjustments. This is all detailed work, done by hand and very time consuming.

This process, called regulation and a final series of tunings complete the music journey of the instrument.

The Finished Product

One final tuning, followed by crating is all that remains. At this point, the piano is shipped to a music store and eventually ends up in a home, church, school or other facility.