Not a comprehensive test, but trimming and smoothing rocky points and uneven surfaces on pathways and dry stacked walls is a common task here, which these disks have done a good job at. Now our work is primarily with limestone, which is a softer stone, and the disk easily and quickly makes cosmetic cuts. They are thin with rapid cutting action, and have been an worth wile addition to our grinder tool bag.

I made one test cut on a fairly thick piece of glass and then chamfered the edge. The cut was clean and the edge turned out sharp without chipping. 

I'm impressed by how well these cut even a very dense, hard stone like quartzite. Great value for the money!!