Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum size of tuning pins...from 2 to 4....or 2 to 3?

Deat Techs,

Looking at a piano that has been restrung.

The owners tech looked at a restringing done twenty years ago and commented...."They used number threes, I would have gone two sizes bigger".

My own piano tech has also made the exact same comment.

I'm thinking this much be significant when two good techs just mention it in passing.

Is it better to go two sizes bigger when restringing? Why?

Thanks,
Newstead

Using oversize pins is a decision making process that involves several considerations.
When used one should ream several existing holes and try some samples to see how the new pins fit. To mention this in passing without putting a tuning hammer on the pins to feel how much torque there is on the originals means nothing. It is better to replace the pin block but if going oversize there is no standard as to one or two sizes over original.

The important thing now is to take torque measurements and determine where the torque is now. While it may have been better to go up 2 sizes what has been done has been done. Sometimes going up 2 sizes can open up cracks in the block especially if the piano is a grand. Going up two sizes will give a snugger fit and increase the torque.The tuning pin threads have a tighter grip on the wood fibers. One down side - if the pins are too tight they tend to flagpole and become snappy. On the plus side tight pins do improve tuning stability.Going up one size may feel tight at first but over time the weather/humidty/temp changes plus the heat created from turning the pins may cause the pins to loose their grip sooner. There are no easy answers . Keep in mind that sometimes it is necessary to restring with various size pins because of the tuning pin hole conditions. Removing old tuning pins generates heat that can enlarge the tuning pin hole.

Changing pin sizes also changes the way the pin feels in tuning; essentially a smaller tuning pin gives a feeling of better control. Many restringers want to go up in size the least possible in order to preserve good tuning pin feel.

There are now replacement pins with oversize lower sections and a regular #2 diameter where the string wraps. These two-sized pins maintain the original "gear ratio" with, potentially, adequate torque in the part of the pin in the block.

It's not unusual to see pianos restrung 20 years ago with 3/0 pins that are now on the loose side. Back then the norm was to go up one size. Most times I've used two sizes larger (4/0)and sometimes I'll put 5/0 in the bass for extra torque. I might go up a size in the middle if they feel too loose as I string. I also pay attention to how the old pins come out, and note any differences in torque. I'll also measure quite a few - I've seen both length and diameter changes across the block in some original stringing jobs.

In my area of the USA, pins are looser in the winter when the air is dry, and tighter in the humid summer months, so I like to take the time of year and relative humidity into account when deciding on tuning pin size.

It's also important the old block be sound. If the old pins were sticky, the new ones will probably be sticky too. Blocks with only one or two laminations don't restring well.

It should also be noted that installing larger pins in a quality piano will hold the value down a bit, compared to installing a new block. Quality pianos should always get the very best.