SELECTION

        A general rule to observe in spring selection is to always use as many springs as the die will accommodate which will produce the required load with the least amount of deflection. This will increase the useful life of the spring, reduce the chances of spring failure and the resulting downtime, loss of production and increased maintenance cost.



        Die spring costs are a very small percentage of the total cost of die. An effort to save a few Rs. on die springs is a misguided act that can cost many Rs. in lost time and labour.



        The more rapidly a spring works, the more attention must be paid to its fatigue limits. In slow moving dies of fixtures, it is possible to get good performance with springs operating near maximum deflection. As the working speed increases, the life expectancy of the spring at that deflection decreases.



        Another approach of selecting a spring is to work back from the amount of operating travel the springs will be subject to as indicated by the die layout. Select springs in the appropriate duty range which will operate efficiently at the required travel. Calculate the no. of springs needed by dividing the load supplied by one spring into the total load required. Round the no. of springs to the next higher even no. for balance performance.