Key Selection Criteria
Highest Precision Capability: Ultra-precision grinding can control part roundness to the 0.001 mm level and surface roughness (Ra) to ≤0.05 μm. When combined with subsequent lapping processes, dimensional errors can be further reduced to the micron level, fully meeting the requirements for nanoscale positioning accuracy in fields such as aerospace and semiconductor equipment.
Strong Suitability for Hard Materials: For hard and brittle materials that are difficult to process via traditional turning or milling-such as alloy steels with post-quenching hardness >HRC 45, cemented carbides, and ceramics-grinding is the most mature and stable finishing method. It avoids issues like tool chipping or part deformation caused by excessive machining stress.
Superior In-Service Performance: Precision components finished via grinding and subsequent refinement exhibit no visible cutting marks and have controllable residual stress states. Radial runout can be kept within 0.003 mm, enabling core components (such as high-pressure piston pumps) to achieve a stable service life exceeding 20,000 hours.
Optimal Process Selection by Scenario
Rotational Parts (Shafts/Sleeves): Prioritize a combination of precision turning and cylindrical grinding. Precision turning can achieve IT6–IT5 tolerances, while subsequent grinding further enhances the accuracy of mating surfaces; this is the standard process route for parts like pistons and spindles.
Parts with Complex Cavities or Multi-faceted Features: Prioritize 5-axis simultaneous milling. This allows multi-sided machining in a single setup, controlling positional tolerances to within ±0.02 mm and eliminating positioning errors caused by multiple re-clamping operations; it is ideal for complex structural parts like mold cavities and aerospace blades.
Hard Material Parts with Micro-profiles or Deep Cavities: Prioritize slow-feeding wire-cut EDM and sinker EDM. These processes are unaffected by material hardness and can machine narrow slots or micro-holes inaccessible to traditional cutting tools. Slow-feeding wire-cut EDM can achieve precision within ±0.002 mm, making it suitable for specialized parts such as precision stamping dies and fuel injector nozzles.
