Made of Bearing steel GCR15 material,smooth surface, high strength and wear resistance, super toughness. Size 1 inch Precision Steel Bearing Balls,Ultra-precision solid steel ball, tough.Ultra-precision wear-resistant, widely used. G25 Bearing Steel Balls Production process: stamping, annealing, hard grinding, fine grinding and other multiple processes to create. 10pcs-high-precision G25 bearing steel ball set Surface treatment: polishing, demagnetization, fine grinding. Scope of application: motors, aerospace, civil vehicles, CNC machine tools, mechanical engineering, bicycles, motorcycles, ships and yachts, etc.