Give credit to Steinway

Steinway was very progressive and forward-looking when they brought out teflon bushings in 1963.

Since the invention of the piano action, "piano people" have understood the problems of cloth bushings. While cloth bushings are durable, they are also troublesome. The fight to maintain a reasonable pin torque is a constant battle, year after year.

Innovation at its best, sees a problem, and brings forth a solution. While often criticized, Steinway engineers saw the problems with cloth bushings and did their best to solve them.

For this they should be lauded. While often accused of cheapening their product, Steinway tried only to make their pianos better.

Unfortunately, Teflon bushings failed.

Teflon Bushings failed for 3 basic reasons:

1. 1. Teflon was too soft, easily deforming under load.


2. 2. Teflon bushings became loose or pinched by the wood depending upon Equilibrium Moisture Content (EMC).


3. 3. Teflon bushings were not executed with precision sufficient to the task.

A hole in wood is circular only at the Equilibrium Moisture Content (EMC) at which it is drilled. As humidity changes, wood changes across the grain but not down the grain. Thus, a hole becomes oval when the EMC is above or below the level at which it was drilled.

In dry weather, when the wood shrinks, the teflon becomes pinched by the oval hole in the wood. The pin torque becomes very high, making the piano very hard to play.

Because the teflon is soft enough to deform, the pressure is able to change the shape of the hole in the bushing.

Later, during the damp season, the hole becomes larger across the grain than it was drilled. The pin tension in the teflon is no longer correct and furthermore, the bushing itself is now free to move in the hole. This resulted in clicking sounds.

Because a hard bushing hasn't the give of cloth, greater precision is required during the pinning process.

None of these problems apply to WNG hard bushings

WNG bushing material does not deform under load:

1. 1. Teflon was too soft and easily deformed. The WNG bushing material is substantially more dense and is thus able to carry the load.


2. 2. Composite action parts are stable during humidity changes and do not alter the cylindrical shape of the bushing. The problems of wood moving around the Teflon bushing--while the bushing did not--are not a problem with WNG composite actions. WNG action parts are not made of wood.


3. 3. WNG uses an extremely accurate process to achieve the necessary accuracy. Any bushing, without give, requires precision. It was true of Teflon and it is true with the WNG bushing system as well. Tolerances need to be tight so no motion of the shaft (center pin) in relation to the bearing is possible. It is this motion that causes clicking.

WNG uses extremely precise stainless steel needle bearings and extremely accurate processes during the pinning process.