According to the national standard GB/T7631.2-2003, hydraulic oil is mainly divided into the following 7 categories:
HL type
Universal hydraulic oil, containing rust and antioxidants, suitable for machine tool bearing housings and low-pressure circulation systems above 0 ℃. It is divided into six grades based on 40 ℃ kinematic viscosity: 15, 22, 32, 46, 68, and 100.
HM type
Anti wear hydraulic oil, with added anti-wear agents, suitable for medium and high pressure systems (such as construction machinery), with viscosity divided into four grades: 22, 32, 46, and 68.
HR type
Containing viscosity index improver, with excellent viscosity temperature characteristics, suitable for medium and low-pressure systems with large temperature differences.
HG type
Combining hydraulic lubrication and anti slip performance of guide rails, suitable for machine tool hydraulic guide rail composite systems, typical grades 46 # and 68 # 12.
HV type
Low temperature anti-wear hydraulic oil, suitable for environments below -25 ℃, with a viscosity index of about 150, commonly used in cold regions.
HS type
Ultra low temperature anti-wear hydraulic oil, based on synthetic oil, with a pour point ≤ -45 ℃, suitable for extreme cold working conditions 12.
