Precision CNC Machining Case for Hydraulic Manifold Block

【Project Background】

This project involved a customized hydraulic manifold block for an industrial hydraulic equipment customer. The part was used as a core oil circuit component to connect valves, actuators and hydraulic pipelines inside the equipment.

The customer provided a 3D model, 2D drawings and hydraulic circuit requirements. The material selected for the part was medium-carbon steel, with multiple threaded ports, cross holes, sealing surfaces and internal oil passages distributed on different faces.

Because the manifold block directly affected oil flow, pressure stability and sealing performance, the project required high accuracy in hole position, thread quality and surface finish.

【Machining Challenges】

The first challenge was the complex internal oil passage structure. Several deep holes and cross holes had to connect accurately inside the block, while avoiding deviation, burrs or blockage. If the hole position or drilling direction deviated, the hydraulic circuit could be affected and the part might fail during pressure testing.

The second challenge was sealing surface control. The valve mounting surfaces and threaded port surfaces needed stable flatness and surface finish to prevent leakage during operation. In addition, the part had many threaded holes with different specifications, requiring accurate tool selection and process sequencing.

The third challenge was cleaning and deburring after machining. For hydraulic components, even small internal burrs or chips may affect valve movement, sealing performance or system reliability.

【Process Solution】

Qingdao SCreate Industrial Technology Co., Ltd. developed a multi-face CNC machining process for this hydraulic manifold block. Before machining, the engineering team reviewed the hydraulic circuit drawings and identified the main datum surfaces, key oil passages and critical sealing areas.

The machining sequence was planned to complete datum surface milling first, followed by multi-face hole drilling, tapping, finishing and deburring. During hole processing, pilot drilling and step drilling were used for deep holes to improve hole direction accuracy and reduce tool deflection.

For cross holes and oil passage intersections, the process team optimized the drilling sequence to ensure accurate connection and reduce internal burr formation. For valve mounting surfaces and sealing areas, finishing passes were applied with controlled cutting parameters to achieve stable flatness and surface quality.

After machining, all threaded ports and internal oil passages were carefully deburred, cleaned and inspected. Compressed air cleaning and visual inspection were used to confirm that no chips or visible burrs remained inside the oil passages.

【Quality Results】

After production, the quality team inspected the hole positions, thread dimensions, sealing surfaces and overall dimensional accuracy. The inspection results showed that the main hole positions and threaded ports met the customer’s drawing requirements.

The valve mounting surfaces maintained stable flatness, and the sealing areas showed no visible machining defects. The internal oil passages were clean and connected correctly, with no blockage found during inspection.

During customer assembly and pressure testing, the manifold block performed stably without leakage. The part met the customer’s requirements for hydraulic circuit accuracy, sealing reliability and assembly consistency.

Through this project, SCreate demonstrated its capability in precision machining of hydraulic components, especially in multi-face hole processing, sealing surface control and internal deburring. This project also provided a stable process foundation for future batch production of hydraulic manifold blocks and related equipment components.