Someone mentioned; <<If you are using the 12-ply block, I have the best luck using .257 bit. With a 2/0 pin, this is drilling .025 undersize. This has given me around 125 inch pounds of torque for several years now.>> I don't think anyone has mentioned it, but I have found that one factor that causes the great variance in pin torque is - how the hole is drilled. I guarantee that you will get different pin torque, using the same drill and block, if you are hand drilling as opposed to using a drill press or a portable drill press set up in the piano. Try it on a piece of scrap pinblock. Also, sharpness of the bit is important. A dull bit will give different torque than a sharp one of the same diameter. A dull drill might be just fine if you know what you are doing and it gives the right torque. Again, try it out on scrap. Here is a pet peeve - Pin bushings. Most technicians say they add nothing to pin torque. I think that is more or less true if they are used as drilling guides and a pin sized hole is drilled through them. If, however, you can drill the pinblock and then install the bushings and string, they add a lot of torque for many years. And the top of the pin is better stabilized where it needs to be. Try an experiment. - Next time you have an old upright with about zero pin torque, one where you can pull the pins out with a vice grips without removing the string, pull out a pin, remove the old pin bushing, install a new one, and put the pin back in through it. You should just be able to tune that note. (temporarily) It can add 20 inch pounds of torque. I know some manufacturers never used them, and I don't like tuning those pianos as much. If not drilled out, I think they also help "seal" the pinblock against rapid humidity changes and the job looks better. Bill Simon Phoenix
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