起重机械所使用的液压油要良好的抗磨性及润滑性。
Lifting machinery used in the hydraulic oil to good abrasion resistance and lubricity.
目的在于降低机械摩擦，保证工程机械的使用寿命。为改善油液的粘度指数，油液中往往加入聚甲基丙烯酯，聚异丁烯等高分子聚合物，这些物质分子链较长，油液流经液压元件的狭缝时受到很大的剪切作用，往往会使分子断链、油液粘温特性下降。
Purpose is to reduce the mechanical friction, ensure the service life of engineering machinery. In order to improve the oil viscosity index, often join methyl acrylic ester oil, polyisobutylene and other polymers, these substances molecular chain is longer, the oil flows through the hydraulic components of the slit by great shearing action, often can make the molecular chain scission, falling oil viscosity-temperature characteristics.
工程机械作业时换向阀的频繁换向，节流元件的节流等都要求液压油有较强抗剪切能力。
Engineering machinery operation frequently the reversing of the reversing valve, throttle of throttling element requires the hydraulic oil has a strong ability to resist shear.
抗乳化性和抗泡性好。抗乳化性的指油液中混入了水并经搅动后成为乳化液、水从其中分离出来的能力。
Good demulsibility and anti-foam. Demulsibility of refers to the oil mixed with water and after agitation become emulsion and water separation ability.
抗泡性是指油液中混入了空气并搅动而生成乳状液，气泡从油中分离出来的能力。混入水或空气后降低油的容积模数，可压缩性增大，液压元件动作迟缓，并易产生冲击和振动。
Anti-foam sex refers to the oil mixed with air and agitation and formation of emulsion, the ability of bubbles comes off the oil. Oil mixed with water or air to reduce the volume of modulus, compressibility, hydraulic components, sluggishness and is easy to impact and vibration.