In properly lubricated bearings, what is true about metal contact?

In properly lubricated bearings, the principle of a lubricant forming a film between the surfaces is critical to their operation. When a lubricant is effectively applied, it creates a barrier that separates the bearing surfaces, which minimizes direct metal contact. This film of lubricant helps to prevent wear by reducing friction and protecting the surfaces from damaging interactions that can occur when metals touch.

The correct answer highlights that in ideal conditions where lubrication is optimal, there should be no metal-to-metal contact, ensuring that the components can function smoothly without degradation from friction. This is essential for maintaining the life span and efficiency of the bearings in various machinery and equipment. In contrast, if there is any significant metal-to-metal contact, it can lead to increased wear and potential failure of the bearing, which is not the case with proper lubrication.