I do quite often mainly for enlarging the vain in a piece. Cut it with a flat blade then go over it wiith a 3/0 F. D. spiral. As a mater of fact I use the clamp to sort of straighten the end. Work it in there than clamp down on it. I do it on both ends. The only spirals I have used are the F.D. 3/0 and the Pegas 2/0. Spiral require a liittle more tension because, I think, when you fire up the machine it stretches out the twists a little so you need to compensate for that at the beginning,,, That is my theory anyway.