The process of installing new hammers (or "hammer hanging" as it is called in the industry), requires a high degree of accuracy. The old hammers are used as a reference for ordering new hammers. Measurements are taken from the old hammers and then a specialized parts manufacturer makes hammers to fit that particular piano. In photo 4HammerGrand, you can see what the hammers look like when they come from the parts manufacturer. These hammers are Renner Blues made for a Steinway Grand. There are several parts manufacturers. Usually the rebuilder chooses the supplier that can produce the hammer that is closest to the what the original was when it was new. The rebuilder takes into consideration what will create the best touch weight, tone and durability for the specific needs of the client..
The cost of hammers is a small percentage of the overall cost of a hammer replacement job. The rest is skilled labor and an organized process to customize the parts for the specific needs of the client and piano. Even before the new hammers are hung, the components on which the hammers swing, called "shanks" and "flanges", must be carefully aligned (or "traveled") so that they move straight up and down. Any sidewise movement is corrected by installing thin paper shims under the flanges. This assures a proper touch and superior tone, when the piano is finished.
Old hammers (called "Sample Hammers") are used to align the new hammers, assuring that the piano stays within the original design specifications when it was originally built. There are special jigs and tools used to perform an accurate and quality job of hammer alignment. After the hammers are installed, the shanks need to be trimmed. In order for the hammers to contact the strings at the exact point conducive to best tone, the hammers need to align properly in several planes. Many more adjustments are made to complete the process of hammer replacement.
Replacing old worn out hammers with new hammers can add new life to an old piano, giving it a rich and deep tone. It is usually desirable to replace shanks and flanges at the same time the hammers are replaced. This will insure the maximum durability and will not waste time and money later. In the photos for this hammer rebuilding section, Master Rebuilder Kendall Ross Bean is installing hammers on a 1920's Steinway Grand and on an 1895 Ellington Upright.
In a typical grand action, there are some ten thousand moving parts. In a comprehensive rebuild, we check each of these parts and then refelt, repin, recondition or replace them to restore the piano to its original glory. It is a very laborious and time-consuming operation. But when the results will be a magnificent instrument capable of pleasing the most discerning artist, it becomes a labor of love.
To read more about the hammer replacement process, click on the first photo in this section to see a larger version and then click next to scroll through the rest of the photos. At the bottom of each photo is a description of the process featured in the photograph.