Hydraulic Manifold Blocks: Machining Requirements That Prevent Leak Paths

Hydraulic manifolds carry high pressure through drilled passages that intersect inside a single block. When one leaks, the cause is almost always a machining decision made weeks earlier.

Flatness and finish at the port face

Sealing faces need controlled flatness and a surface finish fine enough to let the seal or O-ring compress evenly. A face that is nominally flat but wavy will weep under pressure, and no amount of torque fixes it.

Internal passage quality

• Deburr every intersection — a hanging burr inside a passage is a future contamination source.
• Control drill wander on long cross-holes so passages actually meet where the drawing says.
• Pressure-test to the specified rating and document the result per block.

Material and rating

Match the block material to the working pressure and fluid. Carbon steel is often sufficient; stainless or higher-grade alloys are specified where corrosion or weight drives the decision. We confirm the rating before quoting.

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