52100 Alloy Steel Ball, Material Alloy Steel, Material Grade 52100, Ball Bearing Grade 25, Ball Weight 2.99 g, Outside Diameter 9 mm, Rockwell Hardness C60 to C67, Mechanical Finish Polished, Machinability Not Rated, Standards AISI E52100, Outside Diameter Tolerance +/-0.00254 mm, Brinell Hardness 654, Application Aerospace, Automotive, Clean Energy, Factory Automation, Material Handling, Medical, Packaging, Printing, Heat Treatable Yes, Heat Treatment Tempered, Shape Ball