A helical compression spring is to be made with a wire diameter of 2 mm, an out-side diameter of 19 mm, ten active coils, and ends closed and ground. The

least expensive steel spring wire is to be used, and presetting will not be used. (a) Estimate the maximum static load that can be applied without encountering more than 2 percent long-term set. (b) What is the spring rate? (c) At what spring free length will the load determined in part (a) cause the spring to become solid? (d) Would buckling problems be encountered if one end plate is free to tilt? Repeat Problem 12.25, except use a wire diameter of 4 mm and eight active coils.