Peugeot PM03579 Nancy 7 Inch Pepper Mill, Acrylic

Maybe the previous reviewer (et415) had a defective unit, or something other than pepper to grind, but it is not physically possible that "the 'screw' [it's actually a nut] that controls grind fineness becomes loosened as you grind." The lid that you grasp and turn to grind the peppercorns fits tightly over a flattened part of the drive spindle, firmly locking it in place. The nut screws onto the threaded part of the spindle that sticks through the lid. The more you tighten the nut, the higher it lifts the spindle and the inner part of the grinding mechanism at the bottom of the spindle, resulting in a finer grind. The nut, the lid and the spindle move as one since the lid is firmly locked onto the flattened part of the spindle. The nut cannot become loose as you turn the lid. The nut just sits there.
If there is a better-engineered pepper mill out there, I'd like to know about it.

Best pepper mill I've ever had. Sleek and works like a charm. Easy to adjust the pepper grind.

The screw that controls grind fineness becomes loosened as you grind, so you constantly have to adjust it as you grind. Grind volume is OK, but not great. I bought it because it was cheap and it's clear so you can see how much peppercorn you have left. But there are probably better grinders out there.