Technical Reference
What Is Micro EDM
Micro EDM uses very small electrodes and low-energy discharges to produce micro holes, slots, pins, and miniature cavities without mechanical cutting force. Micro EDM cannot compete on speed or bulk removal.
Quick Answer
Micro EDM uses very small electrodes and low-energy discharges to produce micro holes, slots, pins, and miniature cavities without mechanical cutting force.
Concept Summary
What It Is
Micro EDM uses very small electrodes and low-energy discharges to produce sub-millimeter holes, slots, cavities, and profiles without cutting force. Its defining limits are electrode wear, micron-scale gap stability, flushing, and metrology.
What It Can Do
Select it from feature size, electrode size, aspect ratio, edge-radius allowance, discharge stability, and available metrology. When planning Micro EDM, apply the requirement only to the dimensions and faces that control fit, function, service life, or documented release.
What It Cannot Do
Micro EDM cannot compete on speed or bulk removal. When the feature is larger and accessible, standard EDM or CNC is usually faster and cheaper. At micro scale, electrode wear and edge rounding can consume the tolerance band, so a feature that cannot be measured cannot be reliably released.
How It Works
A fine electrode and low-energy pulses remove very small volumes without cutting force. At this scale, electrode wear, gap stability, dielectric access, thermal drift, and optical measurement resolution can be as important as the programmed tool path. This mechanism explains the limits and behavior that matter when planning Micro EDM.
Micro EDM Conditional Planning
| Condition or input | What changes | What must be confirmed |
|---|---|---|
| micro hole, micro slot, miniature cavity, or fine pin | Defines whether the process access is valid | electrode wear, feature-to-electrode ratio, micro-flushing, aspect ratio, edge radius, thermal stability, and measurement resolution |
| Material condition | Changes support, wear, stability, and surface response | Exact grade, condition, and functional faces |
| Depth or section height | Changes flushing, wear, deflection, or metrology | True feature depth, aspect ratio, datum, and inspection |
| Finish stage | Changes texture and final size together | Rough/finish sequence and allowance |
Surface and Edge Effects
At micro scale, electrode wear can round entry edges or make repeated features drift even when the average surface texture is fine. Define edge radius, waviness, feature count, and optical inspection where those details control function. For Micro EDM, tie the accepted condition to the feature and inspection method named in the drawing.
Micro EDM Drawing and Release Checkpoints
- Identify the controlled feature, material condition, access direction, and functional datum for this Micro EDM decision.
- Separate dimensional requirements from texture, edge, recast, corrosion, fatigue, or post-process acceptance.
- State the inspection method, sampling or first-article requirement, drawing revision, quantity, and any documentation needed for release.
Limits and Better Alternatives
Main Limit
For What Is Micro EDM? the guide applies to the named technical decision and does not replace the drawing-specific review of geometry, material, setup, and inspection. When that boundary dominates, use conventional EDM for larger features, precision laser processing for suitable thin geometry, or mechanical micro-drilling where a tool can reach.
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
At micro scale, electrode wear can round entry edges or make repeated features drift even when the average surface texture is fine. Select it from feature size, electrode size, aspect ratio, edge-radius allowance, discharge stability, and available metrology.
What to Remember
Micro EDM uses very small electrodes and low-energy discharges to produce micro holes, slots, pins, and miniature cavities without mechanical cutting force. Use the process only where its physical access and feature limits fit the drawing, then release the result against a named inspection method.
Technical Reference
Use the values as planning references and define the functional requirement on the controlled drawing.
Use This Guide to Prepare Your RFQ
Contact us when your drawing and requirements are ready for review.
- Drawing or part sketch
- Material grade
- Thickness / part size
- Quantity
STEP/STP, DXF, DWG, PDF, IGS/IGES or ZIP.
Confidential drawing review. NDA support available on request.
Frequently Asked Questions
What makes Micro EDM different?
The electrode, discharge energy, flushing gap, and measurement method all operate at miniature scale.
Is finer always better?
No. Smaller electrodes are less stiff, wear faster, and need more stable flushing and metrology.
What matters more than a broad Ra value?
Final feature size, edge radius, electrode-wear compensation, and the functional edge often matter more.
When is Micro EDM uneconomical?
Use another process for loose-tolerance or easily accessible features.