The best grease for bearings depends on several factors including the bearing type, operating conditions, and manufacturer recommendations. Generally, lithium-based greases are widely used and considered suitable for most applications due to their excellent mechanical stability, water resistance, and wide temperature range. For high-speed bearings, a grease with a lower viscosity such as NLGI grade 2 or lower might be recommended to reduce friction and heat generation. For extreme temperatures, synthetic greases like polyurea or silicone-based greases are preferred. It’s crucial to consult the bearing manufacturer’s specifications to ensure compatibility with the grease selected, as using the wrong grease can lead to premature wear, overheating, and ultimately bearing failure. Regular maintenance schedules should also include relubrication intervals to ensure optimal bearing performance and longevity.