Resisting the pressure of rotating iron, stone, cork, and felt as one grinds and polishes, is like Gold’s Gym for your hands.
Many years ago I stopped off at a plumbing supply store to purchase some solder. Discovering I didn’t have my checkbook, the owner smiled and said, “take the solder and mail me a check. I know you’ll pay me, I can tell by your hands.”
As a kid, my mother would tell me I had fingernails like a girl. But that’s another story.