This standard applies to compression and extension springs of class II, category 1 with forces at a maximum spring deformation (F3) of 1.5
GOST 13770-1986 Referenced Document
GOST 13764-1986 Cylindrical helical compression (tension) springs made of round steel. Classification
GOST 13765-1986 Cylindrical helical compression (tension) springs made of round steel. Designation of parameters, methods for determination of dimensions