Improper lubrication accounts for 70% of premature ball bearing failures. This guide outlines precise steps to select grease, control quantity, and apply lubricant to extend bearing lifespan.

1. Common Lubrication Mistakes

Many engineers use incompatible grease types. For example, lithium-based grease fails at temperatures above 120°C, leading to bearing wear. Over-lubrication, exceeding 30% of the bearing’s internal space, causes heat buildup and grease oxidation. Under-lubrication creates friction that damages raceways and rolling elements.

2. Correct Grease Selection for Ball Bearings

Match grease to operating conditions. For continuous operation at 100–150°C, use polyurea-based grease like MS Bearings LGMT 3, which maintains stability under high temperatures. For low-speed (≤500 RPM) heavy loads, choose extreme-pressure (EP) lithium grease. For high-speed (≥3000 RPM) applications, use low-viscosity synthetic grease to reduce drag.

3. Optimal Grease Quantity & Application Method

Apply grease at 20–30% of the bearing’s internal cavity volume. For a 6205-series ball bearing, this equals 0.8–1.2 grams. Use a manual grease gun for small bearings or automatic lubricators for continuous operation. Avoid contaminating grease with dust or moisture during application; clean bearing surfaces before re-lubrication.

What is the typical re-greasing interval for a 6205 ball bearing at 800 RPM?

A 6205 ball bearing operating at 800 RPM under normal load requires re-greasing every 1,500–2,000 hours.

Can I mix different types of bearing grease?

Mixing grease types is not recommended, as it can reduce lubricant performance and cause bearing failure.

For project-specific requirements, consult your bearing supplier. Contact MS Bearings for free technical support.