What are the processing characteristics of precision machining?

Precision machining aims to achieve high machining accuracy and excellent surface quality, and its machining characteristics are mainly reflected in multiple dimensions such as equipment, process, materials, and control. The following is a detailed analysis of its key characteristics:

1、 Extremely high dimensional accuracy and positional tolerance Accuracy level: The dimensional tolerance is usually controlled within ± 0.001~± 0.01mm (IT5~IT3 level accuracy), and some ultra precision machining can reach nanometer level (± 0.0001mm). ▶ For example, the profile error of aircraft engine turbine blades should be ≤ 0.003mm, and the fitting surface tolerance of precision molds should be ≤± 0.005mm. Strict positional tolerance: The requirements for straightness, roundness, parallelism and other positional tolerances are extremely high. For example, the roundness of precision shaft parts should be ≤ 0.001mm, and the flatness of optical lenses should be ≤ 0.0005mm.

2、 Excellent surface quality Low surface roughness: The surface roughness value Ra is ≤ 0.8 μ m, and ultra precision machining can achieve Ra ≤ 0.02 μ m (mirror level). ▶ Application scenarios: Medical devices (such as artificial joints) require low roughness to reduce friction and infection risks; Optical components such as lenses and prisms require mirror level surfaces to avoid light scattering. No micro defects: Surface processing should avoid defects such as burrs, cracks, and burns, which are often achieved through processes such as grinding, polishing, and electrochemical machining (ECM).

3、 Use high rigidity and high-precision equipment Machine tool characteristics: Strong structural rigidity: The bed is made of low thermal deformation materials such as granite and ceramics, and is matched with a double walled frame or symmetrical structure to reduce vibration and deformation. Precision transmission system: using low friction transmission components such as static pressure guide rails, air bearings, and ball screw pairs, the positioning accuracy can reach ± 0.001mm/m. High speed spindle: The spindle speed can reach 10000-100000rpm, and with oil mist cooling or air cooling technology, it is suitable for high-speed cutting of hard materials.