MAXIMUM ALLOWABLE TORSIONAL STRESSES FOR COIL COMPRESSION SPRINGS IN STATIC APPLICATIONS




MAXIMUM ALLOWABLE TORSIONAL STRESS FOR HELICAL COMPRESSION SPRINGS IN STATIC APPLICATIONS (% OF TENSILE STRENGTH)
Material Unprestressed
(Before set removed)
(Includes KW or KB)
Prestressed
(After set removed)
(Includes KS)
Music wire and cold-drawn carbon steel 45 % 60-70 %
Hardened and tempered carbon and low-alloy steel 50  % 65-75 %
Austenitic stainless steels 35  % 55-65 %
Nonferrous alloys 35  % 55-65 %
Source : From Shigley's Mechanical Engineering Design [Ref 2] page 508 and Standard Handbook of Machine Design [Ref-3] Chapter 24 page 19

Note: KW: Wahl factor, KB: Bergsträsser factor, KS: Shear-stress correction factor



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