e type circlips All the Circlips are manufactured from spring steel of grade such as 70C6 or 75C6 confirming to IS : 2507 - 1975 specification for cold rolled steel strips for springs (first revision). Hardness of Circlip is between 460 to 580 HV (Corresponding to 46 to 54 HRC) Surface Finish of E- Type Circlips : Unless the purchaser specifies any alternative finish, the circlip shall be chemically or thermally blackened.