5.25" Pulley end: 5/8"-18 Splined Blade end: 5/8"-18 Star Year Used: '98 to Current Used on Rider 38" Decks. Also known as part number(s): 618-0138P, 618-0138 -- For replacement bearing only order our 442 Bearing . for replacement mounting bolts use our 910-1260 Self Tapping Bolt