I wanted to learn to tune a piano by myself, and bought a relatively cheap size #2 star tuning lever (~$40) for the job. The tuning pins are far too small for my lever.
I am looking for either a place I could find tuning levers of appropriate size or a substitute that will not damage my piano (I have been looking at harp tuning tools as an option).
The tuning pin is so small that it does not catch on the tuning lever (I am able to rotate the tuning lever freely almost without resistance).
With some quick estimation done by a bit of scotch tape and pencil, I estimate that the tuning pins are likely a full millimeter below size 2. I do not think the lever is at fault, as I have some spare #2 pins that fit perfectly with the lever.
If it is of any help, the piano is made by Young Chang (a Korean manufacturer) and has the letters "CM110" on its frame.
Edit: The pins don't appear to be worn down in particular. The piano has been succesfully tuned by professionals before.