Layered tube with controlled flexibility

An all plastic (preferably fluorocarbon) automotive hose has great strength relative to the light weight thereof. The hose (10) is made of an inner layer (14) which has preferably circumferential grooves (18) on an outer wall and an electrically conductive surface (12) on an inner wall. An outer jacket (16) is extruded over the outer wall with the jacket material filling all grooves to provide a mechanical interlocking between the inner layer and the jacket. The cross section of the grooves is selected on a basis of the amount of mechanical movement desired between the inner layer and jacket. Some grooves provide uniform flexibility, some provide progressively greater resistance to bending, and some provide a differential resistance to pending -- more resistance in one direction than in another direction.