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- May 27, 2016
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- 3,471
Though I was taught about stress vs strain diagrams, yield point, plastic deformation, etc. roughly at a time when when gasoline was $0.40/gallon, it seems the same stuff is still the prevailing wisdom.You'd be amazed at what gravity will do with just a little bit of help.
Pure cast iron has no plastic deformation, and come to that, not much stretch either. It is brittle, and weak in tension, and just breaks. Lathe beds like mine (South Bend circa 1942) are made of "semi-steel", a loose term which can cover many grades, but apparently heavy duty, durable, and lower cost.
If it is stressed from being "un-level", so OK, it will deform. Take the stress off, and it should return back to where it started. Provided the yield point was not reached, that should happen right away. If it did yield, but not break, then it will return to a new place, permanently deformed. I did not know there was a "get there slowly" time delay thing involved.