Standard Handbook of Machine Design P29

TABLE 24.12 Maximum Allowable Stresses for ASTM A228 and Type 302 Stainless-Steel Helical Extension Springs in Cyclic Applications Percent of Tensile Strength "f™ ** of Cycles 10 106 107 5 1 In Torsion Body 36 33 30 I End 34 30 28 In Bending _ End 51 47 45 This information is based on the following conditions: not shotpee ned, no surging and ambient environment with a low temperature heat treatment applied. Stress ratio = O. SOURCE: Associated Spring, Barnes Group Inc. 24.5.8 Tolerances Extension springs do not buckle or require guide pins when they are deflected, but they may vibrate laterally if loaded or unloaded suddenly. Clearance should be allowed in...