I use only spiral blades and have no truble with them at all. I use an Excalibur saw and the blade clamp in just fine. I clamp the top first to get the right depth and then the bottom. When I change holes in my work I unclamp the top move to a new hole and reclamp the top, really easy, no blade straightening and I break very few from over tightening.

Mamabogie