CNC Machining or EDM? The honest answer depends on four things: the load the part carries, the environment it lives in, the tolerance the drawing calls for, and the volume you are buying. Below is the comparison we use when we quote both options.
If you already know which one you need, send the drawing and we will confirm it. If you are not sure, the table below usually settles it in one pass.
CNC Machining vs EDM: side-by-side comparison
| Dimension | CNC Machining | EDM |
|---|---|---|
| Cost | Cheaper per part in most cases | Expensive and slow |
| Strength & performance | No thermal effect | Recast layer possible |
| Corrosion / durability | Same as base material | Same, but check the recast layer |
| Machinability & tolerance | +/-0.01 mm, sharp external corners easy | +/-0.003 mm, sharp internal corners easy |
| Lead time & tooling | 3-7 days | 4-10 days |
| Choose it when | The geometry has open access | You need a sharp internal corner or hardened material |
How to decide
- Start with the failure mode, not the price. If the part fails from corrosion, CNC Machining and EDM are not interchangeable no matter what the price difference is.
- Check the tolerance the function actually needs. Tightening tolerance on a material that machines poorly multiplies the cost difference.
- Check availability. A cheaper material with a four-week lead time is more expensive than a dearer one that ships in a week.
- Check the finishing route. Plating and anodizing behave differently on each option and can change the decision on their own.
Where the cost difference comes from
Material price is only part of it. Machining time, tool wear, scrap rate and finishing cost usually decide the final number. A material that costs twice as much but machines three times faster can be cheaper per part. That is why we quote both options with the process route shown, not just a single price.
Frequently asked questions
Is CNC Machining better than EDM?
Not in general. CNC Machining wins when the geometry has open access, and EDM wins when you need a sharp internal corner or hardened material. Give us the drawing and we will tell you which one we would choose and why.
How much more does CNC Machining cost than EDM?
The material cost difference is only one input. Machining time and tool life matter as much. Send the part and we will quote both options side by side so the comparison is real.
Can you machine both CNC Machining and EDM?
Yes. Both are routine for us, and we will say so if one of them is a poor fit for your geometry rather than quote it anyway.
Which one should I use for an export product?
Availability and documentation usually decide it. Both are widely stocked and certified, so the tie-breaker is normally the end user’s specification or the applicable standard.
Related pages
- Comparisons — the full index for this section.
- 5-Axis vs 3-Axis: Real Cost Comparison
- Ra vs Rz: Surface Roughness Parameters
- Passivation vs Electropolishing
- IT6 vs IT7: Tolerance Grade Selection
- Instant CNC quote
- Tolerance quick reference
- Frequently asked questions
Get a price for your part
Send a STEP file and a drawing with tolerances, material and quantity. We quote within one working day and machine in our own facility in Shenzhen — milling, turning, EDM, grinding and finishing under one roof, no trading middleman.
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