A coil spring with plain ends that are ground is to operate with a load that fluctuates between 45 and90 lb, đuring which the deflection is to vary by in.Because

of space limitations, a mea coil diameterof2 in. has been selected. Steel spring wire corresponding to the shot-peened wire in Figure 12.16 is to be used. The beneficial effect of the specified presettingİs not to be taken into account in the calculations.It is considered to provide a sufficient safety factor to allow for the possibility of higher stresses, should the spring ever close solid. Choose an appropriate clash allowance, and determine appropriate values for N.d. andL (See Figure P12.39.