Pianotech

Learned colleagues I crave your guidance.

I very rarely re-string pianos that have tuning pin bushings in the plate. Having installed the new bushings I find the hole to be just under 7/32". Some of my friends and mentors have drilled out new bushings with a 1/4" bit prior to stringing and some have not. I'm restringing a mid 1960's Yamaha with the original block and have chased the holes with a .272" bit prior to installing 2/0 pins. I'm wondering if I should pre-drill the bushings or if I should just hammer through them to add to the pin tightness. What say you all?

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Karl Roeder
Pompano Beach FL
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Hammer away. The bushings will give way to the pins. No problem.

Wim.
Sent from my iPhone

If you don't pre-drill, then the bushing can split, maybe some think the splits look tacky. On re-stringing jobs , I always put in a new block and caps every time.

-chris

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Karl,

It has been my belief that tuning pin torque is to be set by the pin block, not the bushing. It's possible, by not drilling/reaming, the tight bushing may create irregular pin torque, making for an irritating tuning process. I would suggest you ream the bushings after you install them in your plate. The advantage of a reamer is that it doesn't catch in the bushing and inadvertently draw down the drill bit -- possibly into the pin block. 

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Roger Gable RPT
Gable Piano
Everett WA
(425) 252-5000
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Not necessary. If the bushings are tight in the plate holes they won't split. They are very soft and will simply compress. They have no affect on tuning pin torque. 

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David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320
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Karl,

It really depends on the bushings you installed.  The ones available in the US are usually very soft, like Western soft maple.  They will compress pretty easily.

If you bought hard bushings from Yamaha or Kawai, I would pre-drill with the same bit as with the pinblock, but with a depth limiter collar or something so you don't mess up the top of the pinblock hole.

Remember, Yamaha and Kawai pinblocks very often are not fitted to the plate flange, so a tight fitting pin bushing is rather important to the stability!  Alternative is to do an epoxy (with filler) plate flange fit, then the bushings aren't so important.

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Don Mannino RPT
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Thanks for all the replies. The bushings are definitely the soft American type. Fortunately this G2 built in 1965 has a block that's fitted to the plate flange and glued to the cornice as well. Looks like brute force will be the order of the day.

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Karl Roeder
Pompano Beach FL
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I drill them out to .250" anyway. 

Peter Grey Piano Doctor 

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Peter Grey
Stratham NH
(603) 686-2395
pianodoctor57@gmail.com
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Original Message:
Sent: 10-18-2025 19:01
From: Karl Roeder
Subject: drill or no drill?

Thanks for all the replies. The bushings are definitely the soft American type. Fortunately this G2 built in 1965 has a block that's fitted to the plate flange and glued to the cornice as well. Looks like brute force will be the order of the day.

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Karl Roeder
Pompano Beach FL
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If they are soft bushings, and if the block were not fitted to the flange, then it would probably be best not to drill them because the pin bearing on the plate is what keeps the tuning stable so a compressed bushing in that case would be better.  In this case, since the block is fitted, then it probably doesn't matter for that reason.  The soft bushings won't split (in my experience) and until this thread I didn't know that the Yamaha/Kawai factory bushings were a harder material but that would make sense given the requirements for stability.  It also might be that Yamaha/Kawai drill the block (and bushings) in the piano which obviates the need to a stop on the drill if you are drilling the bushings after the fact.  

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David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320
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Original Message:
Sent: 10-18-2025 19:01
From: Karl Roeder
Subject: drill or no drill?

Thanks for all the replies. The bushings are definitely the soft American type. Fortunately this G2 built in 1965 has a block that's fitted to the plate flange and glued to the cornice as well. Looks like brute force will be the order of the day.

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Karl Roeder
Pompano Beach FL
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Original Message:
Sent: 10/19/2025 11:29:00 AM
From: David Love
Subject: RE: drill or no drill?

If they are soft bushings, and if the block were not fitted to the flange, then it would probably be best not to drill them because the pin bearing on the plate is what keeps the tuning stable so a compressed bushing in that case would be better.  In this case, since the block is fitted, then it probably doesn't matter for that reason.  The soft bushings won't split (in my experience) and until this thread I didn't know that the Yamaha/Kawai factory bushings were a harder material but that would make sense given the requirements for stability.  It also might be that Yamaha/Kawai drill the block (and bushings) in the piano which obviates the need to a stop on the drill if you are drilling the bushings after the fact.  

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David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320
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