Technical Reference
EDM Thickness Guide Technical Reference
EDM depth must be interpreted by process: section height for Wire EDM, cavity depth for Sinker EDM, true hole depth for Small Hole EDM, and access depth for Micro EDM. Thickness alone does not define EDM capability.
Quick Answer
EDM depth must be interpreted by process: section height for Wire EDM, cavity depth for Sinker EDM, true hole depth for Small Hole EDM, and access depth for Micro EDM.
Key Technical Points
What the Parameter Changes
Transferring Wire EDM thickness logic to blind cavities or angled holes produces the wrong capability and flushing assumptions. The consequence changes fit, function, or service performance for the Thickness decision; it is not only a change in surface appearance.
How to Select It
Use the dimension that follows the electrode path rather than one generic stock-thickness number. When planning Thickness, apply the requirement only to the dimensions and faces that control fit, function, service life, or documented release.
What Can Go Wrong
Thickness alone does not define EDM capability. Wire EDM uses section height, Sinker EDM uses cavity depth and access, Small Hole EDM uses true hole depth, and Micro EDM uses feature scale and electrode stability; mixing those axes produces false limits.
Technical Context
Thickness changes the length of the active spark path and the ability to flush debris. In Wire EDM it directly changes verticality, wire lag, and mid-span flushing; in sinker, small-hole, and micro EDM the more relevant axis may be cavity or feature depth rather than the outside stock thickness. This mechanism explains the limits and behavior that matter when planning Thickness.
Thickness and Depth Decision Table
| Process | Relevant axis | Thin / shallow condition | Thick / deep condition |
|---|---|---|---|
| Wire EDM | section height | support and flushing pressure dominate on sheet or foil | wire lag, verticality, mid-span flushing, and trim passes dominate |
| Sinker EDM | cavity depth and rib width | floor support and burn-through risk matter on thin walls | electrode wear and debris evacuation dominate deep cavities |
| Small Hole EDM | true path depth / diameter | breakthrough and exit edge dominate shallow holes | runout, taper, flushing, and straightness dominate deep holes |
| Micro EDM | feature depth / electrode size | support and edge quality dominate thin stock | electrode stiffness, wear, aspect ratio, and metrology dominate deep microfeatures |
Surface Considerations
Assign surface, edge, and sub-surface requirements only where they affect function, and give each requirement its own acceptance method. For Thickness, tie the accepted condition to the feature and inspection method named in the drawing.
Thickness Drawing and Release Checkpoints
- Identify the controlled feature, material condition, access direction, and functional datum for this Thickness 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 EDM Thickness Guide, section height or stock thickness alone does not define accuracy, finish, or process suitability; the controlling geometry and process axis still need review. When that boundary dominates, redesign access, split the feature, or use a hybrid route when depth, aspect ratio, or debris evacuation becomes impractical.
Consider Another Route When
Redesign access, split the feature, or use a hybrid route when depth, aspect ratio, or debris evacuation becomes impractical.
Practical Next Step
Assign surface, edge, and sub-surface requirements only where they affect function, and give each requirement its own acceptance method. Use the dimension that follows the electrode path rather than one generic stock-thickness number.
What to Remember
EDM depth must be interpreted by process: section height for Wire EDM, cavity depth for Sinker EDM, true hole depth for Small Hole EDM, and access depth for Micro EDM. Apply the parameter only to named features with a datum, process stage, and measurement 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
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Frequently Asked Questions
Does stock thickness mean the same thing in every EDM process?
No. Each electrode path uses a different depth axis.
What matters for Sinker EDM?
Cavity depth, width, access, ribs, and debris evacuation.
What matters for Small Hole EDM?
True path depth, diameter, angle, and breakthrough.
What belongs on the drawing?
Show the real electrode path and functional acceptance criteria.