I don’t think it is slippage because when I start cutting with a new blade the tension lever on my Hawk is stiff likes it’s supposed to be. The longer I cut the easier it is to flip over and you can tell while you’re cutting that the tension is less. I don’t have that problem with the Pegas blades. I’m going to use up the Eberle blades and I probably won’t buy anymore and stick with Pegas.