... .Hardness: 62Deep groove ball bearings description:1. Material: Gcr15 Chrome steel, Stainless steel or Carbon steel2. Brand: TINMY3. High quality with very smooth ... ,V3,V45. Innder windage code: C0,C2,C3,C4,C56. Precision Grades: P0,P6,P5,P4,P2(ABEC1,ABEC3,ABEC5,ABEC7 ... and gland6.Noise inspection7.Appearance inspection8.Rust prevention9.Product packaging High quality deep groove ball bearings