The strength of a well-crafted instrument makes the piano one of the most impressive examples of engineering and craftsmanship available today. Kawai grand pianos are internationally acclaimed for superior strength and durability.
Rim and beam construction
The RX Series rims are built using cross-banding and lamination techniques which allow them to support the several thousand pounds of constant tension exerted by the strings. The RX Series beams are made of select hardwood laminates, glued together under pressure, making them virtually "isotropic" (equally strong in all directions) and impervious to weather changes and warpage.
Kawai joins the beams to the inner rim using four independent joinery techniques in a single process. Each beam is: (1) doweled... fitted with a hardwood rod, (2) mortised into the inner rim for precise fit, (3) glued, and (4) secured with hardened screws for aggregate bonding strength through the entire thickness of the inner rim.
The plate is the acoustically-neutral, iron superstructure of the piano. It should not transmit or absorb sound energy. Rather, it is the structure over which the strings are tensioned. Therefore, it must be strong and durable. All plates on the RX Series grands are molded using the Vacuum Mold Process. Additionally, the crossbone design provides added strength to the plate. The result is a plate which is both strong and beautiful.
The seasoning process
Wood that contains too much moisture is subject to cracking and other structural concerns. The wood is usually placed in large kilns during an initial de-moisturizing process. Once the wood is properly seasoned, it can adapt to a range of climates. After a long period of seasoning, wood reaches an ideal Equilibrium Moisture Content (EMC) at which it will not give off additional moisture (even in a very dry climate) and will only absorb nominal surface-level moisture (even in the most humid climate). In some cases, wood can take over a decade under the watchful eyes of Kawai's master builders to become fully seasoned.
Kawai knows that there could be many climates within a state. For this reason Kawai waits patiently for this "equilibrium" to arrive to assure that the grand pianos will adapt to a wide range of climates.
Pinblocks and tuning pins
The pinblock is the multi-laminated housing for the tuning pins. It must exert sufficient torque (pressure) on the tuning pins to prevent slippage, yet be forgiving enough to allow the pins to be rotated in either direction for tuning. All RX Series pinblocks are fully laminated with a minimum of 11 cross-banded layers of hard maple. Experience has shown that the finest pinblock construction uses cross-banded, multiple layers of dense hardwood (such as maple), to reach an optimal strength and torque.
Kawai tuning pins are made from the finest "machinery-strength carbon steel"...formulated to withstand the most rigorous pressure and tension. Pins are machine-threaded for maximum continuous torque. Nickel-plating enhances beauty and provides long-term protection.
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