Watch Jeremy Duckles of Supreme Pianos demonstrate how piano hammers are prepared, shaped, bored and installed—and learn when worn hammers should be reshaped, voiced or replaced.
Most piano owners rarely think about the hammers inside their piano—until the instrument begins to sound different.
A piano hammer may look like a relatively simple piece of felt and wood, but it is one of the final connections between your fingers and the sound of the instrument. Every time you press a key, the piano action sends a hammer toward the strings. Over thousands and eventually millions of strikes, those hammers begin to change.
They develop grooves. The felt becomes compressed. Their shape changes. And eventually that wear can affect the tone and performance of the piano.
In the video below, Jeremy Duckles of Supreme Pianos takes you into the workshop and demonstrates some of the detailed work involved in replacing piano hammers, including shaping, boring, preparing and hanging the hammers on their shanks.
What Are Piano Hammers?
Inside an acoustic piano, pressing a key activates a mechanical system called the piano action.
That action eventually propels a felt-covered wooden hammer toward the strings. The hammer strikes the strings and immediately rebounds, allowing the strings to vibrate and produce sound.
A standard piano has 88 hammers—one for each key.
Because the hammers physically strike the strings every time the piano is played, they are wear items. Their condition can have a significant effect on the tone and response of the instrument.
What Happens as Piano Hammers Wear?
If you look closely at the hammers of a well-played piano, you may notice grooves in the felt.
Those grooves are caused by the strings repeatedly contacting the same area of the hammer.
As the piano continues to be played, the felt can become increasingly compressed and the original shape of the hammer can begin to change.
The wear isn't always uniform, either.
Certain sections of the keyboard may be played far more often than others, which means some hammers can show substantially more wear.
That doesn't necessarily mean the hammers need to be replaced.
Sometimes they can be reshaped.
Can Worn Piano Hammers Be Reshaped?
Yes, depending on their condition.
A piano technician can often carefully remove worn felt and restore the proper contour of the hammer. This is commonly called hammer reshaping.
But there is a limit.
Every time material is removed from a hammer, there is less felt remaining.
Eventually a hammer may have been worn or reshaped to the point where there simply isn't enough material left to produce the desired result.
At that point, replacement may make more sense than another reshaping.
This is why the condition of the actual piano needs to be evaluated rather than deciding that hammers should be replaced simply because they are old.
Does a Harsh or Bright Piano Need New Hammers?
Not necessarily.
A piano that has become overly bright, harsh or uneven may have worn hammers, but hammer replacement isn't always the solution.
The piano could need:
- Hammer reshaping
- Voicing
- Action regulation
- Tuning
- Mechanical repairs
- Or a combination of several services
The goal shouldn't simply be to replace parts.
The goal is to determine why the piano no longer sounds or responds the way it should.
That requires looking at the entire instrument.
When Should Piano Hammers Be Replaced?
There isn't a specific age at which every set of piano hammers needs replacement.
A piano that has received light home use for decades may have very different wear than a piano used daily in a teaching studio, church, school or performance setting.
A technician may recommend replacing the hammers when they have become excessively worn, deeply grooved, repeatedly reshaped, or no longer have enough usable felt to achieve the desired tonal result.
Hammer replacement may also be part of a larger piano action restoration.
In that situation, the goal is not simply to install new hammers. It is to restore the relationship among the different components of the action so that the piano can respond properly to the player.
Why Piano Hammer Replacement Requires Precision
This is where Jeremy's video becomes especially interesting.
Replacement piano hammers aren't simply taken out of a box and attached to the piano.
They have to be properly prepared for the action.
Several of the procedures Jeremy demonstrates include boring, shaping and hanging piano hammers.
Each step affects how the finished hammer will function inside the piano.
What Does Boring a Piano Hammer Mean?
The word “boring” in piano restoration refers to drilling the hole in the hammer that will receive the hammer shank.
It sounds simple.
It isn't.
The position and angle of that hole matter because the hammer must ultimately travel toward the strings and strike them correctly.
A small difference while preparing the hammer can become much more significant once the entire action is assembled.
That is why experienced piano restoration involves a great deal of measuring, fitting and careful adjustment.
What Does It Mean to Hang Piano Hammers?
Once the hammers have been properly prepared, they must be mounted onto their hammer shanks.
This process is commonly called hanging the hammers.
Proper spacing and alignment are important.
Remember, you're not installing one hammer.
You're creating an entire row of hammers that must work together as a coordinated system.
Each hammer needs to travel properly through the action and ultimately meet the correct strings.
When the work is complete, the piano owner may never see any of this craftsmanship.
They simply sit down and play.
That's the point.
Why Hammer Alignment Matters
The hammer needs to strike the strings in the proper location and orientation.
That means the relationship between the hammer head, hammer shank, action and strings matters.
An acoustic piano is an extraordinarily precise mechanical instrument.
Much of the restoration work takes place in fractions of an inch.
When dozens of small adjustments are correct, the action begins to feel like one unified mechanism rather than hundreds of individual parts.
What About Renner Piano Hammers and Parts?
You'll notice Renner USA materials in Jeremy's workshop during the video.
Renner is a well-known manufacturer of piano action components used throughout the piano industry.
But choosing replacement components isn't simply about selecting a particular brand.
A piano technician also has to consider the design and condition of the instrument, the existing action and the goals of the restoration.
The better question isn't simply:
“Which brand of hammer should I buy?”
It is: "What components are appropriate for this piano?”
That requires evaluating the instrument itself.
What Is the Difference Between Hammer Replacement, Regulation and Voicing?
These terms are often confused.
Hammer replacement means replacing the existing hammer components.
Regulation deals primarily with the mechanical operation and adjustment of the piano action.
Voicing deals with the tonal characteristics of the instrument and often includes careful work with the hammer felt.
They are related, but they are not the same thing.
Replacing worn hammers may be one part of a much larger process of restoring the performance of the action.
Will New Piano Hammers Change the Sound?
They certainly can.
The hammer is the component that physically strikes the strings, so its condition naturally influences tone.
But the finished sound of a piano is the result of much more than the hammers alone.
The piano's strings, soundboard, bridges, action, regulation, tuning, hammer characteristics and voicing all interact.
Good restoration isn't about making every piano sound the same.
It is about helping a particular instrument perform as well as its design and condition allow.
Is Piano Hammer Replacement Worth It?
That depends on the piano.
For the right instrument, restoring the action and replacing badly worn hammers can make a substantial difference in how the piano feels and sounds.
But extensive restoration isn't automatically appropriate for every older piano.
Before recommending major work, the instrument should be evaluated as a whole.
A good evaluation should help answer three questions:
What condition is the piano currently in?
What can realistically be improved?
Does the proposed restoration make sense for this particular instrument and its owner?
Only then should decisions be made about replacing major components.
Frequently Asked Questions About Piano Hammers
How do I know if my piano hammers need replacing?
Deep string grooves, significant loss of felt, repeated previous reshaping and difficulty achieving the desired tonal result can all be signs that replacement should be considered. A technician should evaluate the hammers along with the rest of the piano action.
Can old piano hammers be repaired instead?
Sometimes. Hammers with enough remaining felt may be reshaped and voiced rather than replaced. The condition of the existing hammers determines which approach makes sense.
What does boring a piano hammer mean?
Boring a piano hammer means drilling the hole that receives the hammer shank. The location and angle need to be carefully established so that the hammer will ultimately be positioned correctly in the piano action.
What does hanging piano hammers mean?
Hanging piano hammers means mounting the prepared hammer heads onto their shanks while maintaining the proper position, spacing and alignment.
Are there 88 hammers in a piano?
A standard 88-key piano has 88 hammers, with one hammer associated with each key.
Will replacing piano hammers make my piano sound better?
When badly worn hammers are limiting the instrument, replacement can make a significant difference. However, the finished result also depends on regulation, voicing, tuning and the overall condition of the piano.
Is hammer replacement part of piano restoration?
It can be. Hammer replacement is frequently performed as part of a more extensive action restoration when the existing components have become worn or are preventing the piano from performing properly.
Thinking About Restoring Your Piano?
If you have an older piano and are wondering whether its hammers or action need attention, the best place to begin isn't by choosing replacement parts.
It's by understanding the condition of the piano.
Supreme Pianos can evaluate your instrument and help determine whether the existing hammers can be reshaped and voiced or whether more extensive action restoration should be considered.
Every piano is different.
And the right restoration starts with the piano that's actually in front of us.
Contact Supreme Pianos to discuss your piano and restoration options.