When selecting radial ball bearings, you must prioritize precision grades (ABEC 1-9), as they determine the rotational accuracy and noise levels. Ensure the load ratings (Static C0 and Dynamic C) align with your machinery's requirements. Material choice is critical; Chrome Steel (GCr15) is the industry standard for durability, while Stainless Steel (AISI 440C) is necessary for corrosive environments. Additionally, verify the internal clearance (C2, CN, C3, C4) to account for thermal expansion during high-speed operations.