Track roller bearing SG 1.Material:GCr15,100Cr6,52100 2.Retainer:nylon,steel cage ... structure Track roller bearing SGDescription:Refined bearing steelPrecision gradeCompetitive price SG LINE TRACK ROLLERSBearing No .Dimension (mm)BallsMass(g)IXINΦdwBoreO ... .10.51425SG2510830148.535.77130.71449SG25-15827.6141030.771311450SG351212421912.548.9318114136 SG U groove track roller bearings