Sinker EDM Services
Machining complex cavities and sharp corners in hardened materials with sinker EDM.A reliable solution for molds, dies, and precision parts.
Advanced Sinker EDM Services
Our Sinker EDM (Electrical Discharge Machining) services deliver exceptional precision for complex cavities, deep ribs, and intricate geometries that are difficult or impossible to machine with conventional CNC milling. By using a custom-shaped electrode and controlled electrical sparks, material is removed from conductive metals without cutting force, ensuring high accuracy and minimal mechanical stress.
Sinker EDM is especially effective for hardened steels, tool steels, and other difficult-to-machine materials, making it a preferred solution for injection mold tooling, precision dies, aerospace components, and complex metal parts. The process allows us to machine sharp internal corners, hidden features, and fine surface details even on fully hardened parts.
At Xtproto, our CNC sinker EDM machining supports both prototype and production runs, delivering tight tolerances, consistent quality, and reliable performance for demanding applications.
Sinker EDM Capabilities
Our CNC sinker EDM services provide advanced machining solutions for complex and high-precision components. Using custom electrodes and controlled electrical discharges, sinker EDM removes material without cutting forces, making it ideal for machining conductive metals and hardened materials that are difficult to process with traditional methods.
This process enables the creation of complex cavities, sharp internal corners, deep ribs, and detailed internal features that are often required in tooling and precision components. Because EDM machining does not rely on cutting pressure, it can maintain excellent dimensional stability even when machining fully hardened tool steels and high-strength alloys.
Our sinker EDM capabilities support prototype development, small-batch production, and full manufacturing runs, providing consistent quality for industries such as mold manufacturing, aerospace, and precision industrial equipment.
Production Capacity
Our Sinker EDM services support projects of all sizes, from early-stage prototypes to low-volume runs and full production:
Rapid Prototyping
Low Volume CNC Machining
High Volume CNC Machining
Materials for Sinker EDM
Our Sinker EDM process machines a wide variety of electrically conductive materials, including common metals and high-performance alloys widely used in precision manufacturing.
Material Category | Typical Uses |
Aluminum | Lightweight parts for aerospace, automotive, and fixtures |
Brass & Copper Alloys | Conductive components, fittings, and electrical parts |
Tool Steels & Hardened Steels | Molds, dies, high strength tooling |
Titanium & Superalloys | Aerospace, medical, and high performance applications |
Tungsten & Carbides | Extremely hard, wear resistant components |
Other Exotic Metals | Specialty alloys for demanding environments |
Because EDM removes material through electrical discharges rather than cutting force, we can machine hardened, high strength, and difficult to cut metals with precision and minimal distortion, making it ideal for precision tooling, dies, and complex industrial parts.
Sinker EDM Tolerances
Our CNC sinker EDM delivers precise, repeatable tolerances for complex cavities, sharp corners, and intricate features. Typical dimensional accuracy ranges from ±0.002″ (±0.05 mm) to ±0.0005″ (±0.013 mm), with high-precision setups achieving ±0.0002″ (±0.005 mm). Tight control of electrode alignment and spark parameters ensures consistent part-to-part accuracy for molds, dies, precision tooling, and aerospace components.
Sinker EDM Surface Finish
Our sink er EDM process delivers precise and consistent surface finishes, ideal for molds, dies, and precision components:
- Consistent & Smooth– Uniform surfaces with no directional tool marks
- Minimal Secondary Work– Fine finishing passes reduce the need for additional post-processing
- High Accuracy on Hard Metals– Maintains surface integrity on hardened steels and high-strength alloys
- Sealed or Leak Proof Surfaces– Perfect for components requiring tight sealing or leak-proof features
- Tight-Fit Features– Ensures precise mating surfaces and high-accuracy fits
- Complex 3D Geometries– Maintains surface quality on intricate shapes and cavities
- Mirror or Polished Finishes– Achievable with additional fine passes for visual or functional requirements
- Micro Features– Handles small, delicate features without damaging the surface
Xtproto Manufacturing Facility
At Xtproto, our factory is built for precision Sinker EDM and CNC machining across a wide range of metals and alloys. Equipped with high-precision 5-axis machining centers and advanced Sinker EDM machines, we handle everything from standard metals to exotic and high-temperature alloys, delivering tight tolerances and exceptional surface finishes.
We support projects of all sizes—from prototypes and low-volume runs to full-scale production—and can accommodate large workpieces with high load capacities while providing micro-machining capabilities when needed. Our skilled technicians ensure complex cavities, sharp internal corners, and intricate geometries are produced consistently and efficiently.
Xtproto’s in-house capabilities include complete electrode production, allowing full control over quality, lead times, and precision. We follow ISO-compliant, quality-first processes, ensuring every component meets exacting standards. Whether your project is in aerospace, medical, automotive, or tooling, our factory delivers reliable, high-precision results on schedule and within budget.
Quality You Can Trust
At Xtproto, every part undergoes strict quality assurance from raw material verification to precision CNC machining and Sinker EDM. Using advanced CMM inspection and multi-stage controls, we ensure tight tolerances, repeatable accuracy, and flawless components for tooling, molds, dies, and critical applications. Learn more on our Quality Assurance page.
Let's Start Your Project
Turn your ideas into reality with Xtproto’s Sinker EDM expertise. Request a custom quote and see how our precision machining handles even the most complex parts. Serving Central Ohio and the Midwest, we deliver tight tolerances and high-quality results for every project.
What Is Sinker EDM Machining And How Does It Work?
Sinker EDM machining (also called ram or conventional EDM) is a type of CNC machining that shapes metal using controlled electrical sparks instead of cutting tools. A custom electrode and the workpiece are submerged in dielectric fluid, and sparks gradually erode material to create deep cavities, sharp internal corners, and intricate geometries.
Because it’s a non-contact process, sinker EDM can machine hardened steels, exotic alloys, and delicate parts without distortion, achieving tight tolerances and precise, repeatable results for tooling, molds, dies, and other precision components.
Sinker EDM Disadvantages
While extremely versatile, Sinker EDM also has some limitations:
- Slower Process– Complex shapes and tight tolerances may require multiple passes and electrode changes, increasing machining time.
- Higher Operational Costs– Consumables like electrodes, dielectric fluid, and maintenance contribute to higher running expenses.
- Limited to Conductive Materials– Only metals and other conductive materials can be machined; non-conductive materials like plastics or ceramics cannot be processed.
- Energy Intensive– The process consumes significant electrical power to generate precise sparks; efficiency depends on optimized parameters.
Sinker EDM Advantages
Xtproto’s Sinker EDM process provides unmatched capabilities for precision machining of complex parts and hard-to-cut materials:
- Non-Contact Machining– Material is eroded electrically, so there’s no physical pressure on the workpiece, protecting thin or delicate components.
- Handles Tough & Exotic Materials– Perfect for titanium, Inconel®, tool steels, carbide, and other alloys that are difficult or impossible to cut with conventional tools.
- Complex Cavities & Sharp Corners– Capable of producing deep cavities, blind holes, undercuts, and intricate internal features.
- High Accuracy & Repeatability– Achieves tolerances as tight as ±0.0002″ with consistent part-to-part results, ideal for tooling, molds, and production components.
- Minimal Post-Processing– Fine surface finish often reduces or eliminates the need for secondary polishing, saving time and cost.
- Precision on Thin or Fragile Parts– Sinker EDM can safely cut thin sheets or delicate components without distortion or damage.
Why Choose Our Sinker EDM Services？
With over 20 years of experience, Xtproto provides precision CNC Sinker EDM machining with exceptional accuracy, efficiency, and flexibility. From single-piece prototypes to low- and high-volume production, our advanced equipment and expert team handle complex geometries, hard metals, and tight-tolerance components, delivering repeatable, high-quality results. Through rigorous quality assurance and multi-stage inspection, we offer custom CNC solutions for molds, aerospace, medical, and industrial applications, consistently meeting or exceeding the most demanding specifications.Xtproto’s in-house capabilities include complete electrode production, allowing full control over quality, lead times, and precision. We follow ISO-compliant, quality-first processes, ensuring every component meets exacting standards. Whether your project is in aerospace, medical, automotive, or tooling, our factory delivers reliable, high-precision results on schedule and within budget.
Wire EDM vs Sinker EDM
At Xtproto, we offer both Wire EDM and Sinker EDM to meet diverse precision machining needs. Wire EDM uses a fine metal wire as the electrode to cut through the workpiece, making it ideal for complex shapes, tight tolerances, and intricate profiles. In contrast, Sinker EDM employs a shaped electrode submerged in dielectric fluid to machine deep cavities, undercuts, and detailed features on larger or harder components. While Wire EDM maintains a constant gap between electrode and workpiece for precise cutting, Sinker EDM removes material gradually, flushing away debris and keeping the workpiece cooled. Choosing the right EDM method depends on part geometry, material, and precision requirements, and our team leverages both processes to deliver high-quality, repeatable CNC EDM components for molds, aerospace, medical, and industrial applications.
Sinker EDM Applications
At Xtproto, our CNC Sinker EDM machining supports a wide range of industries, delivering precision components from prototypes to high-volume production. We machine hard and exotic metals including titanium, tungsten, tool steel, Inconel®, aluminum, copper, and brass, handling complex geometries, blind cavities, sharp inside corners, internal splines, threads, thin ribs, and fine details.
- Tool & Die – We create injection molding molds, stamping dies, and precision tooling, producing intricate cavities and exacting profiles with tight tolerances and excellent surface finish.
- Aerospace & Defense – Our Sinker EDM machines internal cavities, deep ribs, and complex turbine parts in high-strength alloys, ensuring structural stability, lightweight designs, and high-performance components.
- Medical Devices – We produce surgical tools, implants, and precision components from titanium and stainless steel, achieving clean surfaces and micron-level accuracy essential for medical applications.
- Automotive – From molds and valve components to hardened transmission parts, we deliver high-precision, durable components critical to performance and reliability.
With Xtproto’s Sinker EDM capabilities, you get custom CNC solutions for any application requiring tight tolerances, complex features, and repeatable high-quality results, making us a trusted partner across industries.
Request Your Free CNC Machining Quote Today
After receiving your drawings, our engineers will analyze your custom CNC machining parts right away. We actively work with you to clarify all details before providing a quote that is both economical and accurate.