A die spring is well suited for many applications where high static or shock load stresses are required. Rectangular wire is employed to reduce the solid height and increase the space efficiency of the design. Rectangular section are available in a range of different colours and these colours denote levels of duty. The main purpose of the spring is to used in punching mould, metal die-casting mould, plastic injection mould mechanical equipment ç«Â�tamping dies and unipunch .