Bolster Spring For Bvzi To Rdso Drg. No. [Bolster Spring For Bvzi To Rdso Drg. No. Wd-04050-S-02, Alt.-4, Item-5. Other Technical Requirements Conforming To Rdso Spec.No.Wd-01 Hls-94, Rev.5 Of December-2024. Material Grade 52Cr4Mo2V Conforming To Is:3195-1992 With Amendment 1&2. ]