My machinist father in law passed on to me a set of Starrett micrometers, which a friend had given him. They are very old, somewhat blackened with oxidation, but no rust scale or blisters. They are quite stiff. I was thinking about starting with some penetrating oil and working with them a little bit. I'd prefer not to take them apart if it can be avoided. He thought the expression on my face was very amusing when I took them out of the box. There is a 1", 1-2" and 2-3" in the set.