About 40% of industrial bearing failures stem from improper lubrication, a common oversight for engineers and procurement teams. This guide outlines five critical lubrication mistakes and actionable fixes to extend bearing lifespan by up to 30% and reduce unplanned downtime.

Incorrect Lubricant Selection

Choosing the wrong lubricant type accelerates bearing wear by 2x on average. For example, the 6205 deep groove ball bearing—used in motors and conveyor rollers—requires a lubricant matched to operating temperatures: standard lithium-based grease works for -20°C to 120°C, while synthetic polyurea grease is needed for continuous operation above 150°C. Avoid general-purpose grease for high-load applications like construction equipment, as it lacks extreme pressure (EP) additives.

• Lithium-based grease: General industrial use, -20°C to 120°C
• Synthetic polyurea grease: High-temperature applications, up to 180°C
• EP grease: Heavy load conditions (conveyor systems, crushers)

Over-Lubrication vs. Under-Lubrication

Both excess and insufficient grease cause failure. Over-lubrication fills more than 50% of the bearing’s internal space, increasing friction and raising operating temperature by 10-20°C, leading to seal damage. Under-lubrication leaves less than 20% of the space, causing dry friction that shortens bearing life by 60% in continuous use. For 6205 bearings, target a 30-50% grease fill during maintenance.

Contaminant Entry During Lubrication

Dust, moisture, and metal particles introduced during lubrication cause 25% of bearing-related point failures. Always clean the lubrication nipple before adding grease, and use a sealed grease gun to avoid drawing in contaminants. In dusty environments, wipe the bearing surface with a lint-free cloth post-lubrication to remove excess debris.

Wrong Lubrication Interval

Lubrication frequency depends on load and speed: high-speed bearings (3000+ RPM) need lubrication every 1500-2000 operating hours, while heavy-load bearings (e.g., conveyor rollers) require service every 800-1000 hours. Skipping intervals leads to lubricant degradation, while frequent over-lubrication wastes resources. Track operating hours with a simple log to adjust intervals for your application.

Improper Lubricant Application Method

Misapplication, like using a high-pressure grease gun or manual over-pumping, damages bearing seals and causes grease leakage. Use a calibrated grease gun to apply the exact recommended amount, and avoid forcing grease past the seal. For sealed bearings (e.g., 6205-2RS), use pre-lubricated units only—never attempt to re-lubricate sealed bearings as this can compromise the seal.

Contact MS Bearings for free technical support on optimizing your bearing lubrication processes, and for project-specific requirements, consult your bearing supplier.

What’s the maximum temperature a standard lithium-based grease can handle for bearings?

Standard lithium-based greases are suitable for continuous operation up to 120°C; high-temperature variants can reach 150°C briefly.

How much grease should I fill in a 6205 deep groove ball bearing during maintenance?

Fill grease to 30-50% of the bearing’s internal free space; overfilling causes excess heat buildup.