<div class="htmlview paragraph">THIS paper attempts to clarify the functioning of the volute spring and to eliminate the confusion which is at present connected with volute-spring computations. A number of contradictory formulas are currently in use, many of them usable only for one coil or for half a coil at a time.</div> <div class="htmlview paragraph">The paper shows the relationship between the volute spring and other forms of coiled springs; it explains the similarities and dissimilarities of formulas for these spring forms, with particular emphasis on stress determination.</div> <div class="htmlview paragraph">Because of the high stress invariably encountered in some part of a volute spring, it is clear that special consideration must be given to proper bulldozing and load-checking methods, and a set of specifications incorporating these methods is suggested.</div> <div class="htmlview paragraph">In order to steer clear of excessive overstressing and the attendant spring settling, the stress reductions obtainable with partial tapering of the spring blade are discussed in detail.</div> <div class="htmlview paragraph">As a proof for performance results which may be expected from a volute spring design, the life testing of the springs is considered indispensable, and an account is given of results in the past and of prospects in the future.</div>