Online Factory Tour
In
a unique method used by Steinway for over a century, the inner and outer
piano rims are bent into the shape of the rim as a single continuous piece.
Before Theodore Steinway developed and patented this method in 1878, rims
were made of separate pieces held together with joints. 18 hard-rock maple
layers, each twenty-two feet long, are used to construct the rim of a concert
grand piano. The layers are first coated with glue and stacked. The stacked
layers are then glued into a single form of wood by bending on the rim-bending
press, a giant piano-shaped vise. The rim-bending team centers the layers
on the press and wrestles the wood into place with the aid of clamps.
The
soundboard is a large wooden diaphragm with a wooden bridge centered on
its top side. The piano strings pass over the bridge, and the bridge transfers
the string energy into the soundboard. As a result, the sound of the strings
is amplified. The soundboard is pressed into the shape of a dome, allowing
it to withstand the combined downward force of 1,000 pounds from over 200
strings.
The Steinway soundboard is carefully formed, by hand, into a patented Steinway design. Close grained quarter-sawn spruce is used to make the soundboard because the wood is flexible enough to vibrate and therefore project sound, but strong enough to support the weight of the piano's strings. The soundboard is expertly tapered by a craftsman to be slightly thinner at the edges so that it can vibrate properly once it is glued to the piano's inner rim.
Before
a soundboard can be placed into a piano case, the bridge must be notched
for the strings that will pass over it. First, a heavy black graphite is
applied to the top of the bridge. A three-pronged tool is then used to mark
the points where the bridge will be pinned and notched. It takes years of
training for the craftsman to know exactly where to place the notches.
To
ensure cosmetic beauty for a wood-finished instrument, all of the veneer
on a single Steinway piano is cut from the same tree. In the veneer room
of the factory, veneer is cut to size, matched and identified with the piano
number.
The
piano rim is being transformed into a piano case. A wooden brace assembly
is being custom fit within a rim structure. This network of bracing helps
support the 340 pound cast iron plate. The braces fan out within the rim
structure for stability and are secured into the rim by using a combination
of fine joinery and maple dowels.
The arms of the piano are sanded into shape.
Here, a cast iron plate is being fit into a piano case. The 340 pound cast iron
plate provides a rigid and 
stable foundation needed to hold approximately
40,000 pounds of string tension. Graphite has been spread over the portions
of the cast iron plate that come into contact with the rim and pin-block.
The plate is then lowered into the piano case, fitted, and then raised out
of the case. The rim and pin-block surfaces that show print from the graphite
indicate an improper fit with the plate and are shaved to eliminate gaps
between the two surfaces.
Once
the soundboard and cast iron plate are in the piano case, the piano is ready
for its strings. With unerring aim, the stringer inserts a wire through
the hole in a tuning-pin. A machine guided by the stringer turns the pin
three times, wrapping three wire coils around it. The pin is then placed
through one of the more than 200 holes in the cast iron plate and driven
into the pin-block.
The
action's felt hammers are made from a single strip of felt that is pressed
into shape. To form the hammers, glue is first applied to the inside of
the felt strip. The felt is then placed in a long, grooved copper form and
pressed around a three-foot long wood rod into the pear shape of a hammer.
Once the felt has been pressed and removed from the machine, the rod is
sliced. Each piece becomes a hammer which is twirled onto a hammershank.
The wood of the hammershank is sometimes heated by a small flame to make
subtle adjustments in placement.
The
dampers prevent the piano strings from unintentionally vibrating after the
strings have been hit by the hammers. A master technician painstakingly
matches the damper felts to the strings. The technician must then reach
underneath the piano and, with mirrors, adjust the levers that control each
of the dampers.
In a process called the action weigh-off, each key in the keyboard is calibrated to have a consistent feel. Weights are placed on the key and lead is inserted
into the body of the key until the pressure needed to push the key down
is the same for each key.
The voicing process involves minute adjustments to the hammer, which are critical
to the piano's sound and the distinctive personality of each Steinway.
A
master voicer makes adjustments to the hammer's resiliency by sticking the
hammer's felt with a small row of needles, reducing its stiffness and thereby
mellowing its tone. If the voicer wants to increase the brilliance of the
key, he will harden the felt by applying a small amount of lacquer. The
voicer must approve of the tone quality of each key.
A tone regulator listens intently to the piano's pitch and turns the tuning
pins with a tuning hammer to adjust string tension. Once the piano has been
regulated, it is ready for its final inspection.