What are Steinway Teflon action parts, and why don they work properly?
In the 1960’s, Steinway developed Teflon action components which were used from that time until the very early 1980’s. These components feature Teflon circles around the centerpins of all the moving parts of the action components which include the hammershanks, wippens, damper underlevers, and parts of the Sostenuto system and lyre. There were 2 sizes of Teflon circles: small and large. Teflon components can be repinned with special straight reamers and pre-cut pins that are supplied in repair kits still available from Steinway New York. In theory, Teflon will not wear out like a normal felt bushing and can be reamed to an exact standard of friction. This sounds like the perfect material to use on a piano component that requires consistency, right? In practice, the Teflon circle is subject to the changing characteristics of the wood surrounding the material, and therefore pinning becomes inconsistent. In humid weather, the wood swells around the Teflon causing the bushing to tighten up
