Process & Material
Gold Micro EDM General Tolerance + Fine Finish Review
This Gold Micro EDM page combines a General tolerance target with a Fine surface target. These requirements must be planned together because finishing passes improve texture while also changing profile offset, cavity size, hole size, or edge geometry.
Quick Answer
For Gold, ±0.025–0.050 mm and Ra 0.8–1.6 μm are achievable on selected Micro EDM features when electrode wear, gap stability, micro-flushing, thermal control, and measurement resolution are planned together. Apply both targets from the same datum, and reserve the tightest values for the dimensions and faces that control function.
Key Quality Decisions
What These Targets Mean
On Gold, ±0.025–0.050 mm controls the named dimensions and Ra 0.8–1.6 μm controls the named functional faces. In Micro EDM, electrode wear and measurement resolution can consume the tolerance while low-energy finishing changes edge radius and texture. The supplied condition adds a separate risk: surface marking, thin-feature distortion and material recovery can matter more than discharge stability.
Getting Both Targets Right
Use one machining and inspection datum. Apply ±0.025–0.050 mm only to dimensions that control fit, and Ra 0.8–1.6 μm only to functional faces. Plan electrode wear, feature-to-electrode ratio, micro-flushing, aspect ratio, edge radius, thermal stability, and measurement resolution. State the exact Gold condition and the inspection method before releasing the result.
What Gets Missed
On a sub-millimeter hole, slot, or pitch feature specified at ±0.025–0.050 mm and Ra 0.8–1.6 μm, electrode wear and measurement uncertainty can consume the remaining tolerance while the edge rounds during finishing. The tolerance represents a broad size band, while the finishing pass removes enough stock to change edge radius and local size; treating them as independent callouts can make the last finishing step destroy the dimension it is meant to improve. Inspect size, pitch, depth, edge radius, electrode wear, and measurement uncertainty after the final surface step. For Gold, also account for this material-specific risk: surface marking, thin-feature distortion and material recovery can matter more than discharge stability.
How the Targets Interact
For Gold, ±0.025–0.050 mm and Ra 0.8–1.6 μm are linked through the Micro EDM finishing route. Electrode wear and measurement resolution can consume the tolerance while low-energy finishing changes edge radius and texture. The release plan must bind material condition, geometry, datum, finishing stage, and measurement to the same named features.
Micro EDM Capability Reference
| What you're asking | What you can expect |
|---|---|
| Feature types | micro holes, micro slots, miniature cavities, fine pins, and sub-millimeter precision details |
| Tolerance | ±0.002–0.010 mm |
| Surface finish | Ra 0.1–1.6 μm |
| Feature scale | Sub-millimeter holes, slots, and cavities |
| Primary micro limit | Electrode wear and measurement resolution |
| Main limitation | Loose-tolerance or easily accessible features are rarely economical with Micro EDM. |
Quality Target Reference
| Requirement | Planning range | What it means in practice |
|---|---|---|
| General tolerance | ±0.025–0.050 mm | Use one controlled EDM pass where geometry matters more than close fit. |
| Fine finish | Ra 0.8–1.6 μm | Usually needs a finishing pass or lower-energy discharge on the specified surface. |
Material Condition Reference
| Condition | What to expect | Watch out for | Surface notes |
|---|---|---|---|
| annealed | Use stable support and economical roughing. | Clamping and material condition can move delicate features. | Apply fine finishing only to functional faces. |
| work-hardened | Balance dimensional stability with feature-specific finishing. | Residual stress can shift thin sections or small details. | Identify wear, seal, fatigue, or contact surfaces. |
| finished or plated condition | Use conservative energy and selective inspection. | Finished or hardened surfaces can be sensitive to edge damage and recast. | Use lower-energy finishing or post-processing where function requires it. |
Tolerance & Surface Requirements
For Micro EDM at ±0.025–0.050 mm and Ra 0.8–1.6 μm, apply the finish only to the faces named on the drawing. On Gold, use protected fixturing, controlled finishing and recovery procedures for cut-off material. Roughness does not replace recast, edge, corrosion, crack, or post-process acceptance where those items affect function.
Gold Micro EDM Quality Checkpoints
- Mark the dimensions that actually need ±0.025–0.050 mm and use the same datum for machining and inspection.
- Circle the faces that need Ra 0.8–1.6 μm; leave nonfunctional surfaces at a practical production finish.
- State the Gold condition, Micro EDM finishing strategy, measurement method, and any recast or edge requirement.
Limits and Better Alternatives
Main Limit
±0.025–0.050 mm and Ra 0.8–1.6 μm are selected-feature planning references for Gold in Micro EDM, not unconditional whole-part guarantees.
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
Send the Gold drawing with the Micro EDM features that need ±0.025–0.050 mm, the faces that need Ra 0.8–1.6 μm, the supplied condition, quantity, datums, and inspection method.
Practical Takeaway
On Gold, plan ±0.025–0.050 mm and Ra 0.8–1.6 μm together for the selected Micro EDM features. Use one datum and one inspection plan, and apply the tightest values only where they control function.
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.
- Process: Micro EDM
- Material: Gold
- 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.