2Pcs SMR74-2RS Hybrid Ceramic Ball Bearing 4X7Xmm, 440 Stainless Steel(Abec3)

Description Enhanced Performance: Hybrid ceramic ball bearings combine the durability of steel bearings with the lightweight and corrosion-resistant properties of ceramic materials High-Speed Capability: Ceramic Si3N4 balls and AISI440C stainless steel offer superior performance compared to traditional steel bearings, providing smoother rotation, reduced friction, making them great for high-speed and high-precision applications Double Sealed: Sealed on both sides with rubber to protect against dust, dirt, and moisture, ensuring smooth operation and extending its lifespan. ABEC 3 Precision Bearing: Lower manufacturing tolerances compared to lower-rated bearings, resulting in smoother rotation and less friction. Material Shield Type: Double Rubber Sealed Race Material: 440 Stainless steel Ball Material: Ceramic and Si3N4 Selecting Guide Open Type (No Designation Suffix) - Suitable for high-speed and even very high-speed operation. Shielded (Designation Suffix Z/ZZ) - High speed. Protect from dirt and debris. Sealed (Designation Suffix RS/2RS) - Made of sheet steel reinforced nitrile butadiene rubber (oil- and liquid-resistant). Lower limit speed than metal-shielded bearings.