Larry, I have the Porter Cable (PC) saw sold at Lowe's, which I understand is just the same as the Hitachi they used to sell. Although I don't have a lot of experience with spiral blades, I do know that my saw REALLY doesn't like to hang on to standard spirals (and yes, I've cleaned and sanded the ends). It's the design of the blade clamps. Before this I had a cheapo Craftsman that had different style of blade clamps. It held on to spirals without a problem. With my PC, when I clamp the blades in good and tight so they won't slip out , they break very quickly. I have ordered some of the flat ended spiral Flying Dutchman blades from Mike's Workshop. I expect the flat ends will be much easier for my(our) saw/s to hold on to. Like I said, I don't have much experience using spirals, but I've got a couple portrait patterns that are very large and intricate, and I'm sure I won't be able to cut them with standard blades. I'll let you know how the flat end blades work out, they should be here in a couple days.