Ejector Sleeve, plays the role as same as ejector pin in plastic injection mold, the different bettween ejector pin is, ejector sleeve is speically use for some deeper boss in the plastic part, because this area that ejector pin is not possible to use, because there is hole in the middle of boss, if not use ejector sleeve, then hose area will not able to demold, or damage at that area.
SKH 51– JIS High Speed Steel (M2)( 1.3343) equivalent
SKD 61– JIS Die Steel (H1)(BH13)( STD61) (1.2344) equivalent
65Mn, SUJ2, HSS, etc
58 HRC-62 HRC or depending on materials to be processed
Standards: MISIMI/ DIN/ ISI, etc.