I have a 100 year old German baby grand and I need to tweak some of the tuning on a few things. I bought a square entry tuning hammer but once I bring the tuning up (it’s on 430 because not holding concert pitch) the hammer gets stuck on the pin and inevitably once I’ve managed to get it off again I’ve moved the pin.

Should I be using a different shape/size tuning hammer or prepping in some way (they are all a bit rusty etc) I realise tuning is a skill and I could get a pro in but I would like to do this myself (at least the little tweaks). And I’m not up for ditching the piano because it is beautiful and not ready for the scrap heap.

  • Are you certain you bought the correct size key? There's about 4 different sizes.
    – Tim
    Mar 11, 2018 at 16:46
  • Not at all. I’m happy to get another one but not sure what I should be getting. Most of the ones that aren’t cheap Chinese ones (which seem generic) are shipped from the US and I’m not 100% how to ensure I get the right one this time
    – K Haddock
    Mar 11, 2018 at 17:45
  • 1
    @Tim I’d be surprised if there were only 4. Most standardisations like this occurred somewhere halfway the 20th century, so after the OP’s grand was made. Regardless I would not be surprised if all factories still had proprietary pin heads.
    – 11684
    May 10, 2018 at 18:03

2 Answers 2


Yes, from what you've told us it seems clear that you have the wrong size key.


From a purely mechanical perspective the rust definitely wont be helping you. It will help cause binding under tension, so I would recommend trying to remove the rust if you can.

Obviously it's going to be fiddly collecting up the rust, but one technique is to use a vacuum cleaner while rubbing the rust off the pins so that rust doesn't fall into awkward places.

  • With emery paper? I can give that a go. There are only a few notes that are in need of work so I’m not going to have to do the full set luckily
    – K Haddock
    Mar 11, 2018 at 17:46
  • Yes, emery paper is probably your best bet - nice and fine
    – Doktor Mayhem
    Mar 11, 2018 at 18:21

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