... Ball bearing.Roller bearing. hub bearing 2.material,steel GCR - 15 3.Quality authentication ISO 9001:2000 4.Hardness:62 Specifications1.Ball bearing.Roller bearing. hub bearing 2.material,steel ... 51200,51300,51400,DAC,BC, etc. Ring MaterialChrome Steel ,Carbon steel,Stainless steel Tolerance gradeGB/T307.1-205 ID Size 10mm~ ... , HRB, KOYO, LYC, NSK, NTN, SKF 62012RS BALL BEARING ROLER BEARING AUTO-HUB ...