> > Hi Dave, > Something that tight has quite a lot of friction, friction > generates heat, heat on metal causes expansion. Does this set of shanks > have graphited bushing cloth? Examine the pins carefully for score lines. > Just a random thought. > Roger Let's see... A #19 pin is 19*2+10=0.048". I don't know what the thermal expansion coefficient of the material is, but it'll likely be somewhere between copper at 0.00000887, and cast iron at 0.00000556 inches per inch per F°. If we generously make it 0.00001, then a 0.048" pin will expand 0.00001*0.048=0.00000048"per F°. That's, let's see, 0.001/0.00000048= 2083+° per 0.001". How hard did he shake it, again? If you didn't have graphite in the bushing when you started, you'd certainly have carbon in there when you finished. Smoked bird's eye anyone? <G> Ron N
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