What types of lubricants are there?

The components of lubricating oil are base oil and additives, of which base oil accounts for the majority. Base oil is oil, which can be vegetable oil, petroleum fraction, synthetic oil, or some kind of lubricating liquid. Additives are some chemical preparations, and various additives are mixed in the base oil in a suitable proportion. Therefore, from the perspective of composition, lubricating oil is some chemical substances, so it should not be abused in selection, and the appropriate formula should be selected according to the application occasion.

Current lubricating oils can be divided into four types based on composition:

1) Pure mineral oil, without additives:

Ancient lubricating oils were animal and vegetable oils. With the advent of the petroleum age, humans began to use petroleum fractions as lubricants. In the early stages of development, the composition of lubricating oils was mineral oil (petroleum fractions). For example, API-SA grade engine oils belong to pure oil type. Petroleum itself has lubricity and rust prevention. With the development of lubricating oil technology, additives appeared. At present, this kind of pure oil type lubricating oil is hard to find.

2) Mineral oil + additives:

This type of lubricant is the most widely used lubricant at present. It is generally called mineral oil because its base oil uses mineral oil (API-I oil, II oil, III oil). Various industrial lubricants and automotive lubricants, including compressor oil, gear oil, bearing oil, engine oil, hydraulic oil, turbine oil, chain oil, etc., are mostly mineral oils, plus some additives.

The advantage of mineral oil is low price and good cost performance. The operating temperature is generally not recommended to exceed 65℃.

3) Synthetic oil + additives:

This type of lubricant is generally called synthetic lubricant (synthetic oil), which uses synthetic oil as base oil. Among various industrial lubricants and automotive lubricants, synthetic oil is not as common as mineral oil. However, with the increasing requirements of equipment and the increasing attention of users to the quality of lubricants, the use of synthetic oil is also gradually increasing, especially in the field of automotive engine oil.

4) Special oil:

Special oil is also composed of base oil and additives, but special oil is generally suitable for some special purposes. According to the special requirements of users, oil manufacturers specially select suitable base oil (mineral oil or synthetic oil) and specific additives for special purposes. Some oils have special requirements such as explosion-proof, chemical corrosion resistance, and flame retardancy. For example, compressor oil used for some special gases and flammable and explosive gas compressors.

Some synthetic oils can make specific changes in the performance of oil by adjusting the molecular structure, such as PAG and ester oil. Special lubricants are used in applications with special requirements.

It can be seen that when selecting lubricants, it is necessary to understand the composition of the oil. Different types of lubricants will have different performances. When choosing lubricants, it is necessary to start from the oil usage recommendations of the equipment manufacturer, and then combine the actual use of the equipment, including the temperature, load, speed, possible contact substances, whether the equipment is required to not change the oil for a long time, cost and other factors to determine the appropriate type of lubricant.