Application and Technical Requirements of Metal Machined Parts in the Engineering Machinery Field

The operation of construction machinery relies on the coordinated functioning of various components. Metal machined parts within equipment such as excavators, loaders, and cranes undertake core functions including power transmission, structural support, and hydraulic control. According to data from the China Construction Machinery Association, the domestic construction machinery industry's main business revenue reached approximately 900 billion yuan in 2023, with parts manufacturing accounting for 55% to 65% of the total machine cost. This data indicates that the quality of metal machined parts directly determines the operational efficiency and service life of the complete machine.

The hydraulic system is regarded as the "power heart" of construction machinery. Key components such as piston pump cylinders, valve spools, and hydraulic cylinder piston rods are generally made of high-strength alloy steel or stainless steel, processed through CNC precision turning, grinding, and other procedures. The dimensional tolerances of such metal machined parts are typically controlled within ±0.01mm, and the surface roughness must reach below Ra0.4μm. Minor machining deviations can lead to failures such as internal leakage and pressure fluctuations. In a 20-ton class excavator's hydraulic system, there are over 30 types of valve parts alone, each subject to stringent precision requirements.

The transmission system imposes even higher demands on the wear resistance of parts. Components such as gears, shaft sleeves, and bearing housings endure high loads and impact loads over long periods. Materials often used include alloy structural steels like 20CrMnTi and 42CrMo, with surface hardness enhanced through carburizing, quenching, or tempering treatments. In the slewing mechanism of a medium-sized excavator, the raceway machining accuracy of the slewing bearing directly affects the equipment's slewing stability and positioning accuracy. Travel system parts such as track links and drive wheels also rely on precision machining; tooth profile errors exceeding 0.05mm can cause chain derailment or accelerated wear.

Regarding structural components, load-bearing parts such as frames, booms, and arms are large in size and subject to complex forces, requiring a balance between strength and lightweight design during processing. Low-alloy high-strength steels like Q345B and Q690 are widely used, combined with processes such as laser cutting, bending, and welding. The weld quality and dimensional accuracy of such metal machined parts are crucial to the safety factor of the complete machine. Currently, industry standards for fatigue testing of structural components generally require endurance of over 100,000 cyclic loads, with some critical areas demanding up to 200,000 cycles.

Metal machined parts are integral to every functional module of construction machinery, from hydraulics and transmission to structural support. Each segment imposes strict requirements on machining accuracy and material performance. As construction machinery evolves toward larger scales and greater intelligence, component manufacturing processes continue to upgrade. The widespread application of technologies such as CNC machining and online inspection is driving the entire industrial chain toward higher standards.

Qingdao Tianheyuan Metal Co., Ltd. possesses over 20 years of professional casting experience. The company employs the silica sol investment casting process and currently produces over 1,300 tons of castings annually. Most products are exported directly to numerous countries and regions including Europe, North America, Japan, and South Korea. For more information metal machined parts, please feel free to contact us by phone.

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