1. Classification of lubricants

There are many types of lubricants, but they can generally be divided into four categories: liquid lubricants, semi-solid lubricants, solid lubricants, and gas lubricants according to their physical state.

According to the provisions of GBT498-2014 "Determination of Classification Methods and Categories of Petroleum Products and Lubricants", lubricants and related products are classified as L-class products, so the general code of lubricants is L, that is, the first letter of all lubricant codes is L.

(1) Liquid lubricants: including mineral lubricants, synthetic lubricants, animal and vegetable oils, and water-based liquids.

(2) Semi-solid lubricant (grease): Grease is a semi-flowing ointment at room temperature and pressure, so it is also called solid lubricant, which is thickened by base lubricant and thickener in a certain proportion.

(3) Solid lubricants: Solid lubricants are substances that exist in solid form between friction interfaces to lubricate, including soft metals, metal compounds, organic and inorganic substances. Solid lubricating materials commonly used in general industry, such as molybdenum disulfide, graphite, polytetrafluoroethylene, etc.

(4) Gas lubricants: Like liquids, gases are also fluids, which also conform to the physical laws of fluids. Therefore, under certain conditions, gases can also become lubricants like liquids. Commonly used lubricants include air, helium, nitrogen, and argon.

(5) Lubricating oil: Lubricating oil is a liquid lubricant, generally referring to mineral oils and synthetic oils, especially mineral lubricants.

2. The code name of lubricating oil and its significance

(1) According to the provisions of GBT 7631.1-2008 "Classification of Lubricants and Related Products (Class L), Part 1: General Grouping", the code of lubricating oil is composed of categories, varieties and numbers, and its written form is: category, variety, number.

(2) Category refers to the classification of petroleum products. Lubricants are one of the petroleum products, and lubricating material products are represented by L.

(3) Variety refers to the grouping of lubricating oils, which are grouped according to their application, and are represented by corresponding letters: A - total loss system; C - gear; D - compressor; E - internal combustion engine; F - stator, bearing, clutch; G - guide wheel; H - hydraulic system; M - metal processing; P - pneumatic tools; T - steam turbine; Z - steam cylinder, etc., are the first letters of the variety column. In fact, there may be one or more other letters in the variety column To represent further subdivisions of the variety.

(4) The number represents the viscosity grade of the lubricating oil, and its value is equivalent to 40 ° C (some are batch numbers, but it should be noted, otherwise it refers to 40 ° C), which is the intermediate kinematic viscosity value in mm < sup > 2 /s. According to GB/T3141 "ISO Viscosity Classification of Industrial Liquid Lubricants", there are 20 grades of 2, 3, 5, 7, 10, 15, 22, 32, 46, 68, 100, 150, 220, 320, 460, 680, 1000, 1500, 2200, 3200.

Example：L——AN100，Indicates a total loss system lubricating oil with a viscosity grade of 100mm < sup > 2 /s, with a kinematic viscosity of 90 to 110mm < sup > 2 /s at 40 ° C, and a kinematic viscosity of 100mm < sup > 2 /s in the intermediate class.

3. Quality indicators of lubricating oil:

The quality index of lubricating oil can be divided into two categories: one is the physical and chemical performance index of the oil, and the other is the application performance index of the oil. (Mainly introduce several main physical and chemical indicators)

(1) Color: The color of lubricating oil, like all substances, has a corresponding and fixed color, which is related to the refining system of the base oil and the additives added. But during use or storage, it will deteriorate due to oxidation, thus changing the color, and the degree of discoloration is related to the degree of deterioration. If it is milky white, it means there is water or bubbles; if the color becomes darker, it means oxidative deterioration or pollution.

(2) Viscosity: Viscosity is the degree of friction resistance within a lubricating oil, that is, a measure of internal friction. Viscosity is usually divided into dynamic viscosity, kinematic viscosity, and relative viscosity.

Viscosity is the main indicator for the classification, grading, quality evaluation, selection, and substitution of various lubricating oils.

Relative viscosity: Relative viscosity is the viscosity expressed in units of conditions measured by different specific viscometers, generally expressed in three ways: Eng's viscosity, Sai's viscosity, and Reye's viscosity.

Kinematic viscosity: Kinematic viscosity is a measure of the internal friction of a liquid when it flows by gravity. Measurement unit mm < sup > 2 /s; our country divides the viscosity of lubricating oil into 20 grades according to its size, called viscosity grade.

Viscosity is an important quality index of lubricating oil. If the viscosity is too small, it will form semi-liquid lubrication or boundary lubrication, which will accelerate the wear of the friction pair and is also prone to oil leakage. If the viscosity is too large, the fluidity is poor, the permeability and heat dissipation are poor, and the internal friction resistance is large. It is difficult to override and consume high power. Therefore, a reasonable choice of viscosity is the guarantee for sufficient lubrication of the friction pair.

(3) Viscosity-temperature characteristics: The characteristics of lubricating oil change with temperature into viscosity-temperature characteristics.

At present, the viscosity index VI is commonly used to indicate the quality of viscosity-temperature characteristics. The larger the value of VI of a general oil, the greater its viscosity value changes with temperature, so it is more suitable for applications with variable or wide range of temperature. The better the viscosity-temperature characteristics of the oil. The oil with VI = 0 is represented by 0 VI, and the oil with VI = 100 is represented by 100 VI. The viscosity index is an empirical value. It is obtained by comparing two lubricating oils with good viscosity properties (viscosity index is set at 100) and poor viscosity properties (viscosity index is set at 0) as standard oils, based on the viscosity of 40 ° C and 100 ° C.

Classification of viscosity index

(4) Condensation point and pour point

Condensation point: Condensation point refers to the highest temperature at which lubricating oil stops under specified cooling conditions.

Pour point: Pour point refers to the lowest temperature at which lubricating oil can continue to flow under specified conditions.

Both pour point and pour point indicate the low-temperature performance of lubricating oil, but pour point better reflects the low-temperature fluidity of the oil and is better than pour point in practical use. Therefore, internationally, pour point is mainly used to represent the low-temperature performance of lubricating oil. The pour point is about 3 ℃ higher than the pour point, and the working temperature of general lubricating oil is 3-4 ℃ higher than the pour point.

(5) Flash point: Flash point refers to the lowest temperature at which the oil vapor evaporated from lubricating oil is mixed with air under specified conditions, and briefly ignites when it comes into contact with a flame at a certain concentration.

(6) Acid value: Acid value refers to the mass of potassium oxide required to neutralize 1g of organic acids in lubricating oil, measured in mgKoH/g.

The acid value has different meanings for new oil and old oil. For new oil, the acid value indicates the depth of oil refinement, while for 110 oil, the acid value indicates the degree of oxidation and deterioration of the lubricating oil during use. Excessive acid value indicates severe oxidation and deterioration.

(7) Moisture: Moisture refers to the mass percentage of water content in lubricating oil. Due to the presence of moisture, when the temperature drops below 0 ℃, the viscosity temperature characteristics will deteriorate. When the temperature rises, water will vaporize, producing bubbles that destroy the oil film, emulsify the oil, reduce viscosity, and deteriorate lubrication effect.

(8) Mechanical impurities: All solid impurities suspended and precipitated in lubricating oil are collectively referred to as mechanical impurities. The presence of mechanical impurities can damage the lubricating oil film and accelerate the wear of friction pairs.

(9) Residual carbon: Residual carbon refers to the residue formed by heating lubricating oil with air, vaporizing and decomposing it, and finally producing a coke like substance, expressed as a percentage of the oil content.

4. Commonly used lubricating oil:

(1) Total loss system lubricating oil

Total loss system lubricants mainly refer to group A oils in class L lubricants.

L--AN Oil is made from refined minerals and is currently commonly used as a total loss system oil. In the old standard, it became a motor oil or mechanical oil. Its viscosity grades range from L-AN5 to L-AN150, with a total of 10 grades. At 40 ° C, the kinematic viscosity is 4.41~ 165mm < sup > 2 /s, the pour point is not higher than -5 ° C, and the flash point is not higher than 80~ 180 ° C. It is mainly used for light-load, general mechanical total loss lubrication systems or oil-immersed lubrication systems with short oil change cycles. It is not suitable for circulating lubrication systems.

Comparison table between total loss system oil (L-AN oil) and old standard oil and mechanical oil grades

(2) Gear oil

Gear oil is a type L lubricant group C oil. The lubricating oil used to lubricate gear transmissions including turbine worm pairs is called gear oil. The properties it should have are appropriate viscosity, that is, good thermal stability and oxidative stability. Good extreme pressure anti-wear, anti-emulsion, shear stability and anti-rust and anti-corrosion properties. This lubricating oil is generally made by adding corresponding additives on the basis of refined mineral oil or synthetic oil.

Gear oils are divided into three categories: industrial closed gear oils, industrial open gear oils, and vehicle gear oils.

(3) Industrial closed gear oil

Divided into L-CKB、L-CKC、L-CKD、L-CKE、L-CKS、L-CKT、L-CKG Seven levels.

(4) Industrial open gear oil

It is divided into four grades: L-CKH, L-CKJ, L-CKL, and L-CKM.

① L-CKB Oil: used for lubrication of light load or ordinary load industrial gear pairs with gear contact pressure less than 500MPa and gear sliding speed less than 1/3 gear pitch circular speed. The current grades are L-CKB100, L-CKB150, L-CKB220, and L-CKB320.

② L-CKC Oil: suitable for the lubrication of industrial gear pairs with medium and medium loads and no impact loads at working temperatures of -16 to 100 ° C. If the working temperature reaches 100 to 120 ° C, it is only suitable for the lubrication of industrial gear pairs with medium loads. The current grades are L-CKC68, L-CKC100, L-CKC150, L-CKC220, L-CKC320, L-CKC460, L-CKC680 and other seven grades.

③ L-CKD The oil is used for lubrication of industrial gear pairs with operating temperatures between 100 and 120 degrees Celsius, contact pressures greater than 500 MPa, and even impact loads. The current grades are: L-CKD100, L-CKD150, L-CKD220, L-CKD320, L-CKD460, and L-CKD680.

④ L-CKE Oil, used in turbine worm gearing devices with high sliding speed and low efficiency, L-CKE oil is also called turbine worm oil. The current grades are: L-CKE220, L-CKE320, L-CKE460, L-CKE680, and L-CKE1000.

⑤ L-CKS Oil for gear pairs operating at lower, lower, higher constant liquid temperatures and light loads.

⑥ L-CKT Oil for gear pairs operating at lower, lower, and higher constant liquid temperatures and medium loads.

⑦ L-CKG Oil is used for splash lubricated gear pairs in light load continuous operation.

(5) Industrial open gear oil

Industrial open gear oil is divided into L-CKH, L-CKJ, L-CKM and other three varieties, our country is still the implementation of petrochemical industry standards, according to 100 ℃ when the intermediate kinematic viscosity value is divided into 68, 100, 150, 220, 320 five grades.

① L-CKH Oil, used for the lubrication of open gear drives with light and medium loads (< 500MPa pressure) at medium ambient temperatures (-10~ 100 ° C).

② L-CKJ The oil is suitable for the lubrication of open or semi-closed gear transmission pairs with medium ambient temperature and medium or heavy load (7500 MPa) pressure.

③ L-CKM The oil is suitable for the lubrication of open gears operating under heavy load or medium load conditions with impact.

(6) Compressor oil

Compressor oil is group D oil of L lubricant. Compressor oil is a special oil used to lubricate the internal friction parts of the compressor. Including air compressor oil, gas compression oil, refrigeration oil and vacuum pump oil. They are used for compressors under different working conditions. The second letter indicates: "A" means air, "G" means gas, "R" means refrigeration, and "V" means vacuum. The current quotation standard is divided into five grades: 32, 46, 68, 100, and 150.

(1) Air compressor oil

GB/T7631.9 It is stipulated that there are six varieties of L-DAA, L-DAB, L-DAC, L-DAG, L-DAH, and L-DAJ.

① L-DAA Compressor oil is a low-grade compressor oil, suitable for lubrication of compressors with reciprocating exhaust pressure less than 1 MPa.

② L-DAB Compressor oil is a mid-range lubricating oil suitable for the lubrication of medium, high pressure and multi-stage reciprocating compressors. The current national standard is divided into five grades: 32, 46, 68, 100, and 150.

③ L-DAC Compressor oil with a pour point below 40 ° C is suitable for lubrication of heavy-duty reciprocating compressors.

④ L-DAG Rotary compressor oil, suitable for oil injection screw vane compressor, exhaust temperature < 90 ℃, exhaust pressure < 0.8MPa, light load rotary compressor lubrication. The current national standards are divided into: 15, 22, 32, 46, 68, 100 six grades.

⑤ L-DAH Rotary (screw) air compressor oil is suitable for lubrication of medium and low load screw air compressors. The exhaust temperature is less than 100 ° C and the exhaust pressure is 0.8~ 1.5MPa. The current national standard is divided into four grades: 32, 32A, 46, and 46A, of which 32A and 46A are anti-wear rotary (screw) air compressor oils.

⑥ L-DAJ Rotary (screw) air compressor oil for exhaust temperature ≥100℃，A heavy-load rotary air compressor with an exhaust pressure of 0.8 to 1.5 MPa.

(2) Gas compressor oil

GB/T763.9 Gas Compressor Oil TotalL-DGA、L-DGB、L-DGC、L-DGD、L-DGE Five varieties。

① L-DGA It is a highly refined oil and is suitable for lubrication of monoxide compressors under pressure < 104KPa for nitrogen, hydrogen, argon, carbon dioxide, helium, sulfur dioxide, and hydrogen sulfide under pressure < 103KPa.

② L-DGB Specific mineral oil suitable for lubrication in gas compressors with L-DGA oil, but containing moisture and condensate.

③ L-DGC Commonly used synthetic fluids are suitable for lubrication of hydrocarbons under any pressure, ammonia under pressure of > 104KPa, and carbon dioxide compression.

④ L-DGD Commonly used synthetic fluid, suitable for hydrogen chloride, chlorine, oxygen and oxygen-enriched air under any pressure, and lubrication of carbon monoxide compressors under pressure > 103KPa.

⑤ L-DGE Commonly used synthetic oil, suitable for lubrication of nitrogen, hydrogen and argon compressors under pressure of > 104KPa.

(3) Refrigeration oil

There are many varieties of refrigerators, only the refrigeration oil for compression refrigerators. The refrigeration oil requires a low freezing point and good oxidation resistance, but the viscosity is not high. At present, the national standard classifies the refrigeration oil into four grades: L-DRA/A, L-DRA/B, L-DRB/A, and L-DRB/B. L-DRA (Class A) is divided into five grades (grades): 15, 22, 32, 46, and 68, which are suitable for the lubrication of open refrigeration compressors such as ammonia refrigeration compressors and large-capacity Freon compressors. L-DRA (Class B) is divided into six grades (grades) of 15, 22, 32, 46, 68, and 100, which are suitable for the lubrication of semi-enclosed refrigeration compressors such as small and medium-sized Freon refrigeration systems and air conditioning units. L-DRB (Class A) (Class B) has five grades (grades) of 15, 22, 32, 46, and 68 each, which are suitable for the lubrication of refrigerators, cryogenic boxes, and other fully enclosed refrigeration compressors of small automated refrigeration devices.

(4) Vacuum pump oil

Vacuum pump oil has high flash point and viscosity index, extremely low vapor pressure, and good oxidation stability. It is suitable for lubrication and sealing of volumetric vacuum pumps, as well as for gear system lubrication of Roots vacuum pumps. According to the degree of vacuum pumping and gas corrosion, there are six varieties of L-DVA, L-DVB, L-DVC, L-DVD, L-DVE, and L-DVF for selection. L-DVA is suitable for vacuum pumps with low vacuum and no corrosive gases; L-DVB is suitable for vacuum pumps with low vacuum and corrosive gases; L-DVC is suitable for vacuum pumps with medium vacuum and no corrosive gases; L-DVD is suitable for vacuum pumps with medium vacuum and corrosive gases; L-DVE is suitable for vacuum pumps with high vacuum and no corrosive gases, and L-DVF is suitable for vacuum pumps with high vacuum and corrosive gases.

(7) Turbine oil:

Turbine oil, also known as turbine oil, is mainly used for the lubrication of high-speed steam turbines, steam turbine generator sets and large and medium-sized water turbine generator sets. There are four grades of viscosity: 32, 46, 68, and 100. According to GB/T7631.10, our country divides steam turbine oil into steam turbine oil and gas turbine oil. There are four varieties of steam turbine oil: L-TSA, L-TSC, L-TSD, and L-TSE. There are five varieties of gas, including L-TGA, L-TGB, L-TGC, L-TGD, and L-TGE.

(8) Hydraulic oil:

Hydraulic oil is a group H oil for L lubricants. It is used as the working medium in a hydrostatic system (hydraulic transmission system) and is called hydraulic transmission oil. The working medium used in a hydrodynamic system (hydraulic transmission system) is called hydraulic transmission oil. The two are usually collectively referred to as hydraulic oil. There are eight viscosity grades of 10, 15, 22, 32, 46, 68, 100, and 150; the oil used in hydraulic systems is divided into 17 varieties such as L-HH, L-HL, and L-HM, and the oil used in hydraulic systems is divided into L-HA and L-HN.

L-HL hydraulic oil is suitable for the lubrication of low-pressure hydraulic systems in spindle boxes, hydraulic stations and gearboxes or similar mechanical equipment of general machine tools (below 2.5 MPa is low pressure, 2.5~ 8.0 MPa is medium pressure).

L-HM hydraulic oil (anti-capacity hydraulic oil), L-HM hydraulic oil has outstanding resistance compared with L-HL. L-HM hydraulic oil is suitable for vane pump piston pumps with high pressure and ultra-high pressure greater than 10MPa. L-HM hydraulic oil is divided into seven grades: 15, 22, 32, 46, 68, 100, 150.

(9) Bearing oil: Bearing oil is lubricant L group F oil, mainly suitable for precision machine tool main bearings and other high-speed sliding bearings lubricated by circulation, oil bath, and oil pollution. It can also be used as lubricating oil for ordinary bearings and hydraulic system oil.

In the SH/T0017 bearing oil industry standard, in addition to L-FD bearing oil, there is also L-FC bearing oil, which belongs to the anti-oxidation and anti-rust bearing oil. L-FC bearing oil has a total of 2, 3, 5, 7, 10, 15, 22, 32, 46, 68, 100, a total of 11 varieties and grades. Suitable for the lubrication of industrial machinery such as bearings, spindles, gears, clutches, hydraulic systems and steam turbines.

5. Grease

Grease is conventionally called butter or dry oil, a gel-like lubricating material, a semi-solid lubricant between liquid and solid. Grease is synthesized at high temperature by base oil, thickeners and additives, and grease can also be said to be thickened lubricating oil.

(1) The code name of grease and its significance:

The GB/T 7631.8 standard uses grease as a group X lubricant for Class L lubricants, which is suitable for lubrication, various equipment and mechanical parts, vehicles, etc. This standard is classified according to the working conditions of grease, and each variety has a strict code to distinguish different working conditions. According to the regulations, the written form of grease code is: category - group and performance - the number category is the same as the lubricant, represented by the letter L, the group and performance can be composed of 5 letters, the first letter X group; the 2nd to 5th letters represent the minimum working temperature, the maximum working temperature, the water pollution situation in the workplace, extreme pressure performance, etc. The numbers represent the consistency grade, which is divided into 9 consistency grades from 000 to 6 according to its penetration size, with a total corresponding penetration (1/10mm) from 475 to 85.

Example: L-XBEGB00; indicates grease, minimum operating temperature -20 ° C, maximum operating temperature 160 ° C, environmental conditions subject to washing, high load, consistency grade 00.

(2) The old GB/T491-492 standard is based on thickener and penetration, and its code is written in the form of: group and thickener - level - the letter Z is used for the penetration endnote group to indicate the grease, and the thickener is represented by 1 to 2 letters:

Thickener code

Grease grade and grade number

Ordinary grease is not graded, and there is no grade in the code.

The penetration degree directly indicates the serial number of the corresponding penetration degree, and there are 10 serial numbers from 0, 1 to 9.

Endnote and Endnote Codes

Example 1: ZFG-3

Indicates: No. 3 composite calcium-based grease with an penetration of 220 to 250 (1/10mm).

Example 2: ZG-3

Indicates: No. 3 calcium-based grease with an penetration of 220 to 250 (1/10mm).

Example 3: ZFLE-3

Indicates: No. 3 molybdenum disulfide lithium-based grease with an penetration of 220~ 250 (1/10mm).

6. Main quality indicators of grease:

(1) Penetration (cone penetration): Penetration is a common indicator for evaluating the softness and hardness (consistency) of lubricating grease. The so-called penetration value refers to the free fall of the standard cone under the specified quality and temperature (25 ° C). The grease installed in the standard grease cup is vertically passed through the depth of 5S, with a unit of 1/10mm.

(2) Moisture: Moisture is the moisture content of grease grease, and there are two forms of moisture in grease:

One is free water. It is mixed or adsorbed in the grease, which will adversely affect the quality of the grease, reduce the protective performance of the grease, cause corrosion, and reduce the chemical and mechanical properties of the grease.

Another kind of structural water, calcium-based grease contains moisture, which forms a hydrate early with calcium fatty acid, thus playing the role of thickening agent. But lithium-based grease and aluminum-based grease do not allow moisture.

(3) Dripping point: The dripping point refers to the lowest temperature at which the lubricating oil begins to melt and drip the first drop of fluid when heated. The dripping point can determine the maximum temperature allowed when the grease is used. The maximum operating temperature when the grease is required to be selected is 20 to 30 ° C lower than the dripping point.

(4) Mechanical impurities: grease oil mechanical impurities generally refer to solvent insoluble substances, mainly inorganic salts, dust and sand particles falling into the outside world. Mechanical impurities play an abrasive role in the friction pair, destroying the oil film and accelerating wear.

(5) Soap points: the time value of the soap in the grease The soap content in the grease, which is expressed as a mass percentage. The size of the soap points shows the softness and hardness of the grease.

7. Commonly used grease

(1) Calcium based grease: Calcium based grease is made by thickening medium viscosity mineral lubricating oil with natural fatty acid calcium (calcium soap) as a thickener, while synthetic calcium based grease is made by thickening medium viscosity mineral oil with synthetic fatty acid calcium. It is a light yellow to dark brown oil paste that is not easily soluble in water, has strong water resistance, and has good pumpability.

Calcium based grease is suitable for lubricating medium and low load mechanical equipment in industries, agriculture, and transportation, such as small and medium-sized motors, water pumps, blowers, tractors, automobiles, metallurgy, textile machinery, etc. It is used to lubricate rolling and sliding bearings in humid environments with medium and low loads and working temperatures below 60 ℃. GB491 "Calcium based grease" is divided into four grades: ZG-1, ZG-2, ZG-3, ZG-4, with a penetration degree of 175-340; Drip point 80 ℃~90 ℃, calcium based grease is an old product from the 1930s. Due to its low cost and good water resistance, it is still widely used today. However, due to the low drop point and limited operating temperature, lithium based grease is gradually replacing calcium based grease in most domestic and international situations (medium and heavy loads, high operating temperatures).

(2) Sodium based grease: Sodium based grease is made from mineral lubricating oil or synthetic lubricating oil thickened with natural fatty acid sodium soap of medium viscosity. And synthetic sodium based grease is made from medium mineral lubricating oil thickened with synthetic fatty acid sodium soap. It is a dark yellow to dark brown ointment. High temperature resistance, able to work for a long time at a working temperature of 120 ℃, but poor water resistance

GB/T492 sodium based grease is divided into two grades, 2N-2 and 2N-3, with a penetration degree of 220-295 and a drop point of 160 ℃. It is suitable for lubricating friction parts in industrial, agricultural and other mechanical equipment that do not come into contact with water but have high temperatures and low to medium loads. The operating temperature is below 120-135 ℃.

(3) Aluminum based grease: Aluminum based grease is a light yellow to dark brown smooth and transparent oil paste made by thickening mineral oil with fatty acid aluminum as a thickener. It does not contain water and is insoluble in water. Good water resistance, suitable for lubrication of mechanical friction parts in humid environments with working temperatures below 50 ℃. SH/T0371-1992 only has one grade, ZU-2, with a needle penetration of 230-280 and a drop point of 75 ℃.

(4) Lithium based grease: Lithium based grease is made by thickening medium viscosity mineral oil or synthetic oil with natural fatty acid lithium soap as the thickener, while synthetic lithium based grease is made by thickening medium viscosity mineral oil with synthetic fatty acid lithium soap as the thickener. It is a light yellow to dark brown oil paste, and a universal lithium based grease with good water resistance, mechanical stability, rust prevention, and oxidation stability. It is a multi-purpose, long-life, and wide temperature range lubricating grease. Suitable for the flow of various mechanical equipment within a wide temperature range of -20 ℃ to 120 ℃. Lubricant for sliding bearings and lubrication of other friction parts. Suitable for lubrication in humid environments, with a large temperature range, high speed, and high load friction pairs, it is widely used for lubrication of mechanical equipment in various industries such as electric motors, automobiles, tractors, textile machines, mining, metallurgy, and chemical machinery. There are three grades: ZL-1, ZL-2, and ZL-3, with a penetration degree of 220-340 and a drop point of not less than 170-180 ℃.

(Source: Media and Chemical Knowledge Base)