What is a Pin Block? When to Replace a Piano Pin Block

  / livingpianos  
You have probably heard about a pin block and you might have wondered what it is. Well, the pin block is a fundamentally important part of the instrument. In fact, without the pin block, you simply couldn't have any strings on your piano.

The big problem with the pin block is that if it's in bad condition and needs to be replaced you have only one option; rebuild the piano. I've covered the process of rebuilding a piano in prior videos but the short answer for this is basically taking out all the strings and physically removing the plate of the piano -- through the use of heavy machinery. The rebuilding process is the only time you will be able to access the pin block, inspect it fully, and replace it if need be. This is a repair that will cost thousands of dollars.

Needless to say, the pin block is a crucial part of the piano. Its technical job is to keep the pins in place and provide the tension necessary to keep the strings in place; which allows the piano to stay in tune.

Unfortunately, this incredibly important part of the piano can't be inspected for problems easily. If you pull the action out of the piano or remove the fallboard you will be able to see the bottom of the pin block and inspect it. However, the bottom is not where most of the problems will be -- they will be on top.

So how do you tell if your pin block needs to be replaced? There are two main things to look for. The first thing that will point to problems with your pin block is if your piano is unable to hold a tune. If you tune the strings and the pins begin to slip when you apply tension to them, there might be an issue with the pin block. Sometimes this problem can be fixed by using a larger pin size (which is something we will discuss in the next paragraph) but it could potentially make the problem worse. Most likely, the pin block has become cracked and will need to be replaced.

The other occasion to replace a pin block is semi-common and is something that must be done even if everything is working fine. Eventually a piano will have to be restrung -- it's just something that comes with age. However, you can only restring a piano so many times before you have to replace the pin block.

When you first string a piano you use pins called 2-ops. When you re-string a piano you have to use larger pins because the old pins have grooved into the pin block and won't create as much tension -- so a slightly larger pin must be used. Generally you will use a pin that is 2 millimeters in diameter greater than the last ones. So if you replace 2-op pins you will mostly likely be using 4-op pins. Generally you will not want to go past 6-op pins.

So, the short answer to this is that you can re-string a piano twice before having to consider replacing the pin block.

Hope you enjoyed this blog on the importance of pin blocks. If you have any questions or comments feel free to send me an email. Thanks again!