... experience Specification of Taper roller bearings : ItemSpecificationsModelAll 30 seriesMaterialChrome Steel or Stainless steel 304/306Bore size25- ... 33000, etc. Ring MaterialChrome Steel, Carbon steel, Stainless steel Tolerance gradeGB/T307.1-205 ID Size 10mm~ ... , Construction bearing ,Heavy-duty bearing ,tapered roller bearing ,taper roller thrust bearing ,Large bearing.Cage Materialbearing steel ...