-I'm not sure if it's relevant but my pickaxe skill was always 1-2 points above my mining skill when these data were collected.
== Thirst also affects mining action timer ==
The current wiki page under "Notes" at the bottom talks about what affects mining speed but does not include water level. Water level ''definitely'' increases your timer. If start mining with a full water bar at I have a 3 second action timer. As time goes on that first action timer gets longer as my thirst level increases. If I drink water, it goes back to 3 seconds. I haven't confirmed it but I suspect food bar also slows down the action timer for mining.