Machined Surface Finishing

Machined surface finishing removes burrs and sharp edges from machined parts, improving safety, assembly, fatigue life, and surface quality without major geometry changes.

Overview

Machined surface finishing covers post-machining operations like manual, tumble, and vibratory deburring to remove burrs, smooth edges, and clean up tool marks. These processes refine already-machined parts, improving safety, assembly fit, sealing performance, and fatigue life while maintaining the original geometry and tolerances.

Use machined surface finishing when parts come off the machine with sharp edges, hanging burrs, or rough-feeling surfaces that could interfere with assembly, seals, or handling. It fits both prototypes and production, and scales well with small- to high-volume work using appropriate deburring methods. Tradeoffs include extra cost and lead time, minor and somewhat variable material removal at edges, and the need for clear specifications on which features are critical and which can be freely deburred. Well-defined edge and finish requirements keep costs under control and avoid over- or under-processing.

Common Materials

  • Aluminum 6061
  • Aluminum 7075
  • Mild steel 1018
  • Stainless steel 304
  • Stainless steel 316
  • Titanium Grade 5

Tolerances

±0.001" to ±0.003" edge stock variation on deburred features

Applications

  • Hydraulic manifolds and ports
  • Valve bodies and sealing faces
  • Gearbox and pump housings
  • Medical device housings and brackets
  • Aerospace brackets and fittings
  • Precision machined fixtures and tooling

When to Choose Machined Surface Finishing

Choose machined surface finishing when burr removal, edge breaking, and basic cosmetic cleanup are required on machined parts without changing their core dimensions. It suits parts with intersecting holes, threads, pockets, or sealing surfaces where burrs risk leaks, assembly issues, or injury. Use it for anything from one-off prototypes to production batches where consistent, safe edges and reliable assembly are critical.

vs Polishing

Choose machined surface finishing when you primarily need burr removal, safe handling, and functional edges, not a high-gloss or mirror surface. Polishing targets appearance and very low roughness; deburring focuses on making as-machined parts functional and safe with lower cost and less aggressive material removal.

vs Coatings

Use machined surface finishing when the issue is burrs, sharp edges, or minor tool marks, not corrosion resistance or wear performance. Coatings add protective or functional layers; deburring should happen first so coatings adhere properly and don’t lock in burrs or sharp edges.

vs Painting

Prioritize machined surface finishing when you need clean edges, no burrs, and reliable fits before any color or branding is applied. Painting addresses appearance and environmental protection; finishing comes first to prevent burrs cutting through paint or interfering with fits after painting.

vs Heat Treatment

Select machined surface finishing when dimensional accuracy and edge quality are your main concerns on already-hardened or as-machined parts. Heat treatment changes material properties like hardness and strength; deburring complements it by making parts safe to handle and fit correctly, often both before and after heat treat depending on distortion and scale.

vs Hard Coatings

Use machined surface finishing when you need to clean up edges and remove burrs prior to applying hard coatings such as nitriding or PVD. Hard coatings won’t fix burrs and can make sharp edges even more hazardous; deburring first ensures coated parts maintain functional, safe edge conditions.

Design Considerations

  • Specify edge conditions explicitly (e.g., "break edges 0.2–0.5 mm" or "no visible burrs"), not vague notes like "deburr all edges"
  • Call out critical surfaces and edges on the drawing so the shop knows where to protect geometry and where more aggressive deburring is acceptable
  • Avoid extremely deep, narrow slots and blind holes that trap media; if unavoidable, flag them so the shop can plan manual or localized deburring
  • Add small chamfers or radii in the CAD model on edges that must be broken consistently instead of relying on uncontrolled hand deburring
  • Indicate allowable surface finish (Ra) ranges on functional surfaces so the shop can choose manual vs vibratory/tumble methods appropriately
  • Provide section views of intersecting holes and ports, and note which internal edges must be burr-free to avoid assembly, leak, or contamination issues