Deep groove ball bearings are the most widely used rolling element bearings, but selecting the wrong type leads to premature failure. The core solution is to match bearing size, material, and sealing to your load, speed, and environment. For example, a conveyor belt bearing needs higher radial load capacity than a fan bearing, so size 6205 (25mm bore) works for light loads, while 6306 (30mm bore) handles heavier radial forces.
1. Match Bearing Bore Size to Shaft Diameter
Shaft diameter directly defines the bearing’s inner bore size, a critical first step. Common metric bore sizes for industrial bearings include 10mm, 20mm, 25mm, and 30mm; a 25mm shaft requires a bearing with exactly 25mm inner diameter, like model 6205. Oversized bores cause shaft misalignment and increased vibration, while undersized bores lead to tight fits that damage the shaft during installation. MS Bearings provides precision-ground bores with P6 tolerance, ensuring consistent fits for high-speed applications.2. Calculate Radial and Thrust Load Requirements
Bearings support two primary load types: radial (perpendicular to the shaft) and thrust (parallel to the shaft). Deep groove ball bearings excel at radial loads, handling up to 10% of their rated radial load as thrust. For example, a pump bearing with 5000N radial load needs a bearing with a dynamic radial load rating (Cr) of at least 5500N. Dynamic load rating is a key specification; MS Bearings lists Cr values for every model in its catalog to simplify quick selection. A quick comparison of standard models is below:| Bearing Model | Bore (mm) | Dynamic Radial Load (kN) | Max Speed (RPM, Grease-Lubricated) |
|---|---|---|---|
| 6205 | 25 | 19.5 | 12,000 |
| 6306 | 30 | 32.8 | 10,000 |
3. Account for Operating Speed and Temperature
Maximum operating speed depends on bearing design and lubrication type. Grease-lubricated deep groove ball bearings reach up to 15,000 RPM for small 6200 series models, while larger models like 6306 cap at 10,000 RPM. For environments with temperatures above 120°C, use high-temperature lithium complex grease and heat-treated steel ring bearings. Standard bearings lose hardness at high temperatures, leading to early wear. Avoid open bearings in dusty or wet areas, as contaminants cause surface damage.For project-specific requirements, consult your bearing supplier. Contact MS Bearings for free technical support.What is the difference between 6205 and 6306 deep groove ball bearings?
6205 has a 25mm bore, 52mm outer diameter, and 15mm width; it handles up to 19.5kN dynamic radial load. 6306 has a 30mm bore, 72mm outer diameter, and 19mm width, with a 32.8kN dynamic load rating, suitable for heavier industrial loads.
Do I need sealed or open bearings for dusty environments?
Sealed bearings (like 2RS) are ideal for dusty areas; they prevent contamination and retain lubricant. MS Bearings’ sealed deep groove ball bearings have rubber seals rated for -40°C to 120°C, suitable for outdoor conveyor and fan applications.
