What is the significance of the number '6' in the bearing code SKF - 6106?

The number '6' in the bearing code SKF - 6106 is significant because it denotes the type of rolling element used in the bearing. In this context, the '6' specifies that the bearing is designed with a certain rolling element configuration, which helps in categorizing the bearing type. Understanding the type of rolling element is crucial for applications, as different rolling elements—such as balls or rollers—affect the bearing's performance characteristics, including load capacity, speed, and friction.

Option B highlights the importance of knowing the rolling element type, which is vital when selecting bearings for specific applications, as it directly influences the overall functionality and suitability of the bearing in various mechanical setups.