Profile: Die Spring is an importer & stockist of high quality die springs, pins & punches and guide post. Polyurethane die-springs, pads & punch-strippers are offered as perfecthane in polyether-elastomers that react similarly to an incompressible fluid. The volume of material moved by compression is displaced laterally in the form of bulging sides. An approximation to the change in diameter of one of our standard cylindrical urethane springs can be made by increasing the diameter by the inches of compression.