EDM machining isn’t just different—it does what traditional tools can’t. It removes metal with electrical discharges instead of cutting force, allowing for extreme precision without physical contact.
At Roberson Machine Company, we use EDM to solve tough manufacturing challenges: sharp internal corners, ultra-thin features, hardened metals, and delicate post-treatment work. If your part is complex or brittle, EDM machining might be the right solution.
Below, we’re going to dive into the connections between EDM machining and precision manufacturing:
- What exactly EDM machining is (and how it works)
- Why EDM shows up after CNC work is done
- How EDM fits into high precision manufacturing
Have questions? Contact us for a quote or call us at 573-646-3996 to learn how EDM can take your design from “close” to “exact.”
What Is EDM Machining?
Electrical Discharge Machining (EDM) is a process that uses controlled electrical sparks to shape metal. There’s no physical contact—just a wire or electrode, a dielectric fluid, and a whole lot of precision.
At Roberson Machine Company, we use both wire EDM and sinker EDM to make parts for the aerospace and defense, oil and energy, in medical CNC machining, and in other industries. When traditional machining hits its limit, EDM picks up the slack.
EDM machining and its role in precision manufacturing is all about doing what regular tools can’t. It doesn’t drill. It doesn’t grind. It burns metal with tiny electrical sparks—thousands of them—while submerged in fluid, shaping the part without ever making physical contact.
CNC milling machines have their limits. They rely on spinning tools, which means:
- They can’t reach sharp internal corners
- They push on the part (which can flex or distort delicate features)
- They struggle with fully hardened materials
If a part is heat-treated, thin-walled, or packed with fine detail, CNC might get you 90% there. EDM finishes the job cleanly and accurately.
Where EDM Meets Precision Manufacturing
Precision manufacturing is all about having the right tools, being able to repeat production quality, and delivering end products that meet spec the first time. CNC machining covers most of the process—but for fine features, hardened materials, or extremely tight geometry, EDM takes it across the finish line.
Why EDM Makes the Difference
Some manufacturing requirements are simply out of reach for traditional machining techniques. EDM fills that gap. Here’s where it earns its place in your shop:
- Adding ejector pin holes to hardened mold inserts
- Cutting sharp internal corners a CNC endmill can’t reach
- Slotting titanium or tungsten without distortion
- Finishing heat-treated parts without reintroducing stress
- Drilling micro holes in surgical components—clean and burr-free
- Forming deep, narrow ribs in aerospace or die components
EDM isn’t a replacement for CNC—it’s the precision step that follows it. CNC shapes the part. EDM finishes what cutting tools can’t.
EDM’s Role in the Manufacturing Workflow
EDM isn’t a mass removal tool. It’s surgical. Most manufacturers use it when a part:
- Has already been heat-treated and can’t tolerate more distortion
- Needs sharp corners, fine holes, or thin walls
- Is made from ultra-hard or exotic material
- Requires zero contact force to avoid warping or cracking
EDM is a late-stage process. It’s the final step for features that CNC, grinding, or milling can’t produce with enough accuracy—or without risk.
What EDM Can Do That CNC Can’t
- Cut fully hardened steels, carbide, Inconel, and titanium
- Create sharp inside corners (no tool radius to worry about)
- Work on fragile, thin-walled, or heat-sensitive parts
- Machine features after heat treatment—no rework or warping
- Leave parts burr-free and often finish-ready
That’s why you’ll find EDM in every industry where tolerance, finish, and repeatability leave zero room for compromise.
EDM Solves Design Problems
EDM solves real-world design and manufacturing challenges. It gives engineers the freedom to develop parts for function first without being boxed in by cutter size, tool reach, or post-machining distortion.
Take sharp internal corners, for example. Conventional endmills can’t make them—they leave a radius based on tool diameter. EDM cuts with an energized wire or electrode, not a spinning bit, so corners can stay sharp and true to CAD. That opens the door for better-fitting components, precise mating surfaces, and cleaner assemblies.
It’s the same story with deep, narrow features. Need a long slot in hardened steel? A cavity with steep walls? EDM machining makes it possible—no chatter, no deflection, no secondary operations. You’re not stuck balancing tool breakage against geometry loss.
EDM Makes Prototyping Smarter & More Efficient
Flexibility is everything when you’re working on a one-off part or early prototype machining. EDM helps speed up iteration because there’s no need for custom fixturing, special form tools, or post-machining cleanup. Just build the electrode or program the wire path, hit go, and get results.
You can test real-world materials around prototypes before committing to production-level tooling with EDM technology. Contact our team if you’re interested in more information or a quote.
EDM Solves Consistency Problems in Production
EDM isn’t just for prototypes and outliers. It’s ideal for adding precision features late in the workflow—after heat treatment, coating, or surface finishing. That means no rework, no distortion, and no margin for error lost in post-processing. In production, it’s a way to drive consistency and reduce scrap, especially for high-value or high-precision parts.
Whether you’re solving clearance issues, improving fit, or dialing in critical features, EDM gives you another gear to work with without redesigning the entire process.
Precision EDM Machining With Roberson Machine Company
EDM delivers the most value when it’s part of a complete, well-integrated process. Because we also handle CNC machining, multi-axis work, prototyping, and other value-added services, we use EDM exactly where it makes sense within your workflow.
Our team at Roberson Machine Company brings more than 20 years of experience to every job with the tools and insight to take your part from concept to production. Contact us today or call 573-646-3996 to get started on your next project that calls for EDM, precision machining, or both.
