Karen the FD spiral blades are tricky to control not because they break. Spiral blades they cut in 360 degree and not like a flat blade that only cuts on one side. If you can run a sewing machine you will have little trouble using a spiral blade. I like them for simple reason you can cut forward , backward , side to side with out having to turn your work peice. Just takes a little time and practice to be able to control them.
John