I recently changed out the drive pistons in my lawnmowers hydo-drive.  They are 1 1/4" long and 5/8" across.  Straight walled and thimble shaped.  The wall thickness 1.5 mm thick.  Hard as a rock! Any ideas what I could make from them.  I welded one to a piece of stock and it works as a nice round touch mark. Don't get me wrong, this would be great if my last name ended in "O"  or I was a ghost but... I thought of some uses for wood working. Gouges and round chisels and the like. 

Gasket punches, use on a press as general pushem out material.