Do sliding bearings count as standard components?

It shouldn’t be counted; please have an expert answer.

They are considered standard components, only the standards applied vary!

There are standards for sliding bearings, but they are generally manufactured according to customer orders; very few are produced in accordance with standards. Therefore, sliding bearings are not typically standard components. A sliding bearing is a bearing that operates under sliding friction. Sliding bearings operate smoothly, reliably, and noiselessly. Under liquid lubrication conditions, the sliding surfaces are separated by the lubricating oil and do not come into direct contact, which also helps to **reduce frictional losses and surface wear; furthermore, the oil film possesses certain vibration-damping capabilities. But the starting frictional resistance is high. The part of the shaft that is supported by bearings is called the journal, while the component that fits against the journal is called a bearing bush. The layer of friction-reducing material cast on the inner surface of a bearing bush to improve the friction properties of its surface is called a bearing lining. The materials for bushings and bearing liners are collectively referred to as sliding bearing materials. Sliding bearing applications are generally in high-speed, light-load operating conditions. Common materials for sliding bearings include bearing alloys (also known as Babbitt or white metal), wear-resistant cast irons, copper-based and aluminum-based alloys, powder metallurgy materials, plastics, rubbers, hardwoods, and carbon-graphite, polytetrafluoroethylene (Teflon, PTFE), modified polyoxymethylene (POM), etc.