Rectangular Section. Die springs are primarily used in die machinery.For die springs, blue color here represents that the loading grade is light load.Additionally, we want to tell you the loading grade of die springs in various colors (from lightest load to heaviest load): yellow, blue, red, green, brown.However, because die springs are well suited for high stress applications, they are also suitable for a variety of other applications as well.FAQ: What is Hole Dia? What is Rod Dia?
Hole Dia: The Diameter of the Hole on the Mold ,i.e.the Outer Diameter of the spring.
Rod Dia: The Diameter of the Rod that is to be inserted into this spring, i.e.the inner Diameter of the spring.