How CNC Turn-Mill Machining Reduced Valve Spool Scrap Rate by 80%

A German hydraulic systems manufacturer faced efficiency bottlenecks in precision valve spool machining. Their traditional process required three separate operations on three different machines, with single-piece processing time reaching 45 minutes and an 8% scrap rate due to accumulated errors.

The customer's main products were high-pressure hydraulic valve assemblies. The core valve spool component required concentricity between outer diameter and radial holes within 0.01mm, with surface roughness below Ra0.8μm. Monthly demand was approximately 2,000 pieces.

We developed a customized CNC turning-milling process: utilizing a turning-milling center equipped with powered turret and Y-axis to complete outer diameter precision turning, end face groove milling, and radial hole drilling in one operation. Optimized cutting parameters (cutting speed 100m/min, feed rate 0.12mm/r) ensured machining stability.

• Single-piece processing time reduced from 45 minutes to 28 minutes
• Scrap rate decreased from 8% to below 1.5%
• Concentricity consistently controlled within 0.008mm
• Surface roughness achieved Ra0.6μm

This case demonstrates the significant advantages of turning-milling technology in precision hydraulic component manufacturing. By eliminating accumulated errors through one-clamping operation, both processing efficiency and product consistency are improved.