NSK Bearings 6311 1.Deep groove ball bearings 2.High Precision-P4,P5,P6 3.Competitive Price,Chinese bearing manufacturer NSK Deep Groove Ball Bearing 6311 About product: 1) Types: 60 series, 62 series, 63 series, 64 series. 2) Corresponding models range :605-6020 ,623-6220 ,6300-6320 ,6403-6413 3) Material: Gcr15 (Chrome steel) -China, (AISI) 52100-American, (Din) 100Cr6 -Germany, carbon steel, ...