CNC Sleeve Turning

CNC sleeve turning is our specialized service for hollow shaft parts with length more than 3 times the diameter. Sleeves differ from bushings. Sleeves are typically more slender with thinner walls and higher length-to-wall-thickness ratios. They are more difficult to machine. Our CNC sleeve turning serves oil drilling tools, hydraulic cylinder tubes, printer photoconductor drums, medical device cannulas, and optical instrument tubes. Materials include stainless steel (304, 316), alloy steel (4140, 42CrMo), aluminum alloy (6061, 7075), and engineering plastics (PEEK, POM). Every sleeve we produce meets exacting straightness and wall thickness requirements.

The biggest challenges in sleeve machining are thin-wall deformation and straightness control. We use dedicated mandrel fixtures (supporting the workpiece from the inner bore) or thin-wall specialty chucks with precisely controlled clamping force. This minimizes clamping deformation. Our machining strategy prioritizes "roughing → stress relief → finishing." After roughing, we allow 24 hours of natural aging for stress relief. Then we perform finishing. This ensures long-term dimensional stability. We use boring and reaming processes for internal bores. Sleeve inner bore cylindricity is controlled within 0.01mm. Straightness is within 0.02mm per 300mm. Wall thickness deviation is within 0.02mm.

Quality control for CNC sleeve turning focuses on inner bore size, wall thickness uniformity, and straightness. We use internal micrometers and pneumatic gauges for inner bore measurement. Ultrasonic thickness gauges check wall thickness uniformity. Straightness measuring instruments verify axis straightness. For sleeves requiring end fit, we control coaxiality between both ends. This ensures smooth assembly. Inner and outer surfaces are free from scratches and dents. Every batch includes complete inspection reports. Our CNC sleeve turning serves oil drilling and medical device industries. Parts are used in demanding pressure-bearing and precision guidance applications. Standard production takes 20-35 days. We accept orders starting from 1 piece. Standard warranty is 1 year. We provide full-process services including heat treatment and surface treatment (chrome plating, nitriding, anodizing).