The hydraulic system is like the blood vessels of the human body. If the wrong oil is selected, the efficiency will be halved at best, and the pipe will burst and shut down at worst. The national standard GB 11118.1 divides hydraulic oil into five categories: HL, HM, HG, HV, and HS. Each letter is a password lock for the life of the equipment.
HL (ordinary hydraulic oil): basic mineral oil, suitable for low-pressure vane pumps (<7MPa), containing antioxidants and rust inhibitors, but no anti-wear formula. Commonly used in light-load equipment such as machine tools, the annual oil change cost can be reduced by 15%, but high-load conditions will accelerate the wear of the pump body.
HM (anti-wear hydraulic oil): adding zinc/ashless anti-wear agent, the pressure resistance is increased by 3 times (above 21MPa), becoming the standard for excavators and injection molding machines. Note: zinc-containing formulas may react electrochemically with silver parts.
HG (guide rail hydraulic oil) = HM + anti-climbing agent, specifically to solve the problem of low-speed vibration of machine tool guide rails. Actual measurements show that the use of HG oil can increase positioning accuracy by 0.02mm.
HV (low temperature hydraulic oil): pour point as low as -36℃, viscosity index＞130, Arctic scientific research equipment verifies its -45℃ cold start capability. After switching to HV for mining equipment in cold regions, the winter failure rate drops by 40%.
HS (synthetic hydraulic oil): polyalphaolefin (PAO) base oil, life span is 3 times that of mineral oil.
