A flexible, elongated catheter tube having distal and proximal ends and a laser cut section there between. The laser cut section makes up a majority of the catheter length and is cut in a continuous helical pattern forming interlocking teeth which can be sinusoidal, triangular, square or likes shapes, preferably sinusoidal. The interior of the catheter tube has a polymeric bi-layer of a nylon or like polymer at the interface of the tube interior and a Teflon or like polymer forms the interior lumen of the catheter. The exterior of the tube has a thin polymer coating of nylon or the like. A short portion of the distal end is uncut and is followed by a narrower terminal section which can be tapered for better blockage penetration. The interlocking teeth disengage and reengage in a fish scale manner without undergoing plastic deformation and without substantial polymer separation.