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Micro EDM Machining

Micro EDM uses very small electrodes and low-energy discharges to create miniature conductive features. It creates features too small or delicate for conventional EDM and mechanical cutting, with no cutting force on fragile walls and miniature edges.

Quick Answer

Choose Micro EDM from feature size, electrode size, aspect ratio, discharge stability, edge-radius allowance, and the resolution of the inspection method. Loose-tolerance or easily accessible features are rarely economical with Micro EDM.

Key Process Decisions

When to Choose This Process

Typical planning tolerance is ±0.002–0.010 mm, with Ra 0.1–1.6 μm as the broad finish context.

What to Watch For

Electrode wear and edge rounding can consume the tolerance at miniature scale. The metrology plan must be practical before the geometry is released. We manage this by checking access, support, discharge conditions, and inspection before release.

How the Process Works

Micro EDM works with discharge energy below 100 μJ—roughly one-tenth of conventional EDM. At this energy, individual craters can be smaller than a micron across, which is what makes features down to about 0.02 mm possible. But the spark gap is only about 2–10 μm wide, so micron-level electrode wear or debris can close it and cause a short. Dielectric must be driven through this gap, electrodes may need replacement during the job, and aspect ratios beyond about 10:1 become progressively harder to hold because wear, gap stability, and measurement uncertainty consume the feature tolerance.

Micro EDM Capability Reference

What you're askingWhat you can expect
Feature typesmicro holes, micro slots, miniature cavities, fine pins, and sub-millimeter precision details
Tolerance±0.002–0.010 mm
Surface finishRa 0.1–1.6 μm
Feature scaleSub-millimeter holes, slots, and cavities
Primary micro limitElectrode wear and measurement resolution
Main limitationLoose-tolerance or easily accessible features are rarely economical with Micro EDM.

Surface Control

At micro scale, edge rounding, burr-free transition, and electrode-wear compensation can matter more than one overall Ra value.

Micro EDM Drawing Checkpoints

  • Choose Micro EDM from feature size, electrode size, aspect ratio, discharge stability, edge-radius allowance, and the resolution of the inspection method.
  • State the material grade, condition, controlled dimensions, and the functional surfaces that need Ra 0.1–1.6 μm.
  • Use the same datum scheme for machining and inspection, and identify any report or sample-approval requirement.

Typical Parts and Features

  • micro holes
  • micro slots
  • miniature cavities
  • fine pins
  • microfluidic details
  • precision contact features

Limits and Better Alternatives

Consider Another Route When

Use conventional EDM for larger features, precision laser processing for suitable thin geometry, or mechanical micro-drilling where a tool can reach.

Practical Next Step

For a Micro EDM quote, send the drawing, material grade and condition, critical dimensions, surface requirements, quantity, and inspection expectations. If the process route is unclear, send what you have and we will map each feature to the appropriate EDM method.

Practical Takeaway

Micro EDM creates micro holes, slots, and miniature cavities that are too small for conventional EDM or ordinary cutting tools.

Request a Machining Feasibility Review

Send material grade, drawing files, tolerance and quantity. We confirm process fit before quoting.

Quote readiness
  • Drawing or part sketch
  • Material grade
  • Thickness / part size
  • Quantity
  • Tolerance and critical dimensions
  • Surface finish or inspection requirement
Accepted files

STEP/STP, DXF, DWG, PDF, IGS/IGES or ZIP.

Confidential drawing review. NDA support available on request.

Frequently Asked Questions

When should I choose Micro EDM?

Choose Micro EDM from feature size, electrode size, aspect ratio, discharge stability, edge-radius allowance, and the resolution of the inspection method. It creates features too small or delicate for conventional EDM and mechanical cutting, with no cutting force on fragile walls and miniature edges.

What usually limits Micro EDM?

Loose-tolerance or easily accessible features are rarely economical with Micro EDM. Electrode wear and edge rounding can consume the tolerance at miniature scale. The metrology plan must be practical before the geometry is released.

What tolerance and finish can I plan for?

Use ±0.002–0.010 mm and Ra 0.1–1.6 μm as planning ranges. Geometry, material condition, finishing passes, and inspection determine the released result.

What should I send for review?

Send the drawing, material and condition, functional dimensions, surface callouts, quantity, and inspection requirements. If some items are unknown, send the available files and we will help define the missing points.