On 10/29/2010 8:40 AM, Porritt, David wrote: > Alan: > > I’ve always attributed this to the heat and the side to side stress of > the filing. I have no scientific proof but I always questioned the idea > of stressing the new pins when it’s just not necessary. > > If you have noticed as you remove old pins from a famous piano factory, > many were installed point side down, and others round side down. That’s > why they had to file the tops to hide the irregular installation. Well, the pins were originally very crudely made, and I'm not so sure they (when the procedure was established) had rounded tops. The bridges were, and still are as far as I know, hand drilled. So, given nasty looking pins and holes of random depth, the obvious way to make them look neat is to drive the pins to the bottom of the hole and even them up with a file on top. I think it's a manufacturing expedient, lowering the skill level and time needed for installation. Ron N
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