> While taking off the plate bolts of a Steinway L (c1961) I noticed the > plate coming up at the tail. This isn't all that unusual, from what I've seen. Sand cast plates, cooling in specific areas at specific rates that were influenced by non-specific climate conditions at the time of casting, are likely to go in all sorts of unlikely directions. So far, I've been served fairly well by the premise that a little flex in a cast iron plate isn't all that critical below an undisclosed or undefined threshold. I don't claim to know what that threshold is, but from what you've posted, I wouldn't worry about the flex necessary to torque the plate back down where it was. The manufacturer's agent that set it up that way in the first place wasn't apparently worried about it, and the plate didn't demonstrably suffer as a consequence. I've seen worse without obviously disastrous consequences, so I doubt that it's reason for too much concern. I'm far more concerned about the practice of cranking nose bolts down to increase bearing locally, than in a slight twisting of a plate on installation. Ron N
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