Kawai's "Ultra-Responsive™ Action" stands alone in providing the finest combination of strength, stability, precision and reliability. Hammer heads are underfelted and made with 100% premium wool felt. Hammer shanks are made with top-quality maple. To make the action resistant to climatic and seasonal changes in temperature and humidity, Kawai pioneered the use of aluminum action rails, aluminum hammer rest rails and precision parts made of extremely stable, low-friction ABS Styran.

The innovative use of ABS Styran in all our piano actions is one of the chief reasons why a Kawai piano will maintain stable touch and tone over time better than other pianos. Endorsed by leading piano technicians and proven superior in scientific tests, ABS Styran is supported by over forty years of proven reliability in Kawai pianos.

This pivotal link between the key and hammer is made of carbon and polyacetal rather than wood. Its superior composition and patented design make the Carbon Jack stronger, more consistent and more reliable than any traditional wooden jack.

These finely-threaded action screws fasten more securely to the action rail than traditional self-tapping sheet metal screws. Lock washers and pre-threaded action rails further ensure the stability of the action screws and hammer flanges.

The entire surface of the action rail is finely serrated to hold hammer flanges securely in place for more accurate hammer alignment and superior tone.

The malleable character of our exclusive "Insuliner" seats the hammer flange in place at the critical end point to further secure flange alignment and provide optimum tone.

The action rail is the "spine" of the piano's action. Kawai action rails are made of durable extruded aluminum with our exclusive "dualbeam" design for superior strength and stability.

Kawai utilizes no fewer than five die cast action brackets to provide maximum support to the action rail. The die cast process provides exceptional precision in the crafting of brackets, further assuring precise action alignment and superior piano tone.

The exceptional precision and dimensional consistency of the action brackets allows the action rail and wippen rail to be permanently locked in place, providing unparalleled long-term stability to the action.