... types : deep groove ball bearing , self-aligning ball bearings, cylindrical roller bearings, spherical roller bearing , tapered roller bearing , thrust ball bearing , thrust roller bearing 3. Bearing name :Deep groove ball bearing4 ... . Material : Chrome steel ,stainless steel ,bearing steel6.Seal type: open, Z, ZZ, RZ, RS,2RS 7.High precision, low noise 8. Material: Gcr15 ...