Advantages of Wire EDM
Wire EDM cutting is the go-to manufacturing process for cutting complex metal parts with tight tolerances – beyond what’s possible with CNC machining. Fathom is one of the leading shops in the country for wire EDM services, with over 20 years of experience in getting excellent results with it.
When Precision Matters
Because wire EDM manufacturing cuts metal using a thin electrode, it can cut metal to a tolerance of .002 in. With trim passes, that can be increased to .0002 in. It also makes possible features like thin walls, internal corners with very small radii and blind pockets. Wire EDM manufacturing is also ideal for tough materials like Inconel, tungsten and titanium.
Advantages of EDM Manufacturing
Part Geometry
With wire EDM manufacturing, the workpiece is stationary and is not subject to cutting forces. That makes these types of geometries possible:
- Thin walls
- Internal corners with very small radii
- Thin slots in extrusion dies
- Blind and high-aspect ratio pockets (using sinker EDM)
- Non-round openings and cavities
- Broaching for 2D shapes like gears
Hard Materials
Material hardness has little effect on EDM wire cutting rate and doesn’t limit possible part geometries. Tungsten carbide, tool steel, Inconel and any metal harder than RC38 are all good candidates where conventional machining is slow and expensive.
A particular benefit is the ability to bring parts to their final size after heat treatment. This takes out distortion brought about by hardening and stress-relieving.
Surface Finish
Unlike conventional processes, an EDM surface has a very random texture. This is advantageous when directionality or “lay” could influence product performance. Additionally, EDM can create surface finishes as smooth as 5 RMS or around 4 micro-inches Ra. (This entails taking multiple skimming passes, for which the wire EDM cutting rate needs to be very low.)
Cost Advantages
On the right job – complex 2D geometry, hard material – EDM manufacturing offers cost savings over conventional processes. For example:
- No special tooling (saving money and lead time.)
- Skimming passes eliminate secondary finishing operations.
- You can laminate layers of material to cut multiple parts simultaneously.
- It enables reuse of cut out slugs rather than producing chips.
- It avoids moving a part through multiple conventional processes. The final shape is achieved in a single set up (which also improves accuracy)
Limitations of Wire EDM Manufacturing
EDM requires an electrically conductive workpiece. It will not work on wood, plastics or composites.
Material removal rates (MMR) are usually lower than for conventional processes. However, direct comparisons are difficult to make since material hardness is such a big factor. MMR is usually calculated in cubic inches per hour with 0.4 in3/hr a typical rate. Calculated this way, a narrow kerf makes the wire EDM cutting rate quite high. Also, workpiece thermal conductivity and melting point have significant impacts on EDM MMR.
Wire EDM can only cut 2D profiles, although a fourth axis to incline the wire enables conical forms and tapers.
Wire EDM Specifications and Tolerances
Wire EDM offers great precision, even when used with hard raw materials. Tighter tolerances and higher cutting accuracies are possible with Wire EDM. To improve accuracy, lower speed and power may be used. Reduced power and flushing pressure results in +/- 0.0005” tolerance.
Material Thickness | Tolerance | Kerf | Part Volume | Set Up Cost | Lead Time ** | Notes | |
---|---|---|---|---|---|---|---|
WIRE EDM | 0.001″ – 15.0″ | 0.0001″ | 0.005″ | 1-High Volume | Low | 6-8 days | Conductive Metals |
**Dependent on geometry, volume and material: EXPEDITE options available.
Wire EDM Materials List
Wire EDM should be used with any conductive metal such as titanium, aluminum, brass, alloys, and superalloys. Thanks to wire EDM’s accuracy, wire EDM has become a popular manufacturing method for various industries. Whether for part or prototype, Fathom has many materials suitable for wire EDM, including:
- Copper
- Carbide
- Tungsten
- Bronze
- Carbon steel
- Inconel
- Stainless steel
- Hastalloy
- Kovar
- Titanium
- Carbon graphite
- High alloy steel
Wire EDM Finishing
Wire EDM is used to produce a smooth, mirror-like finish, but some finishing may still be required to customize a part. Common finishing processes that can be used for wire EDM parts include:
Painting
Painting a part adds color, varnish, or ink. The painting process may include powder coating, liquid coating, or e-coating. Powder coating uses an electrostatically charged powder which produces a scratch-resistant and uniform coat on the metal part. When a part is liquid coated, wet paint is applied. The e-coating process involves dipping the part into a bath of paint where both the part and paint are electrified, causing the paint to adhere to the part.
Transfers
Transfers apply a label or design to a part. During the transfer process, a design is placed onto the part and pressure is applied through a heated press. Transferring can also be used to print a design that may later be engraved onto the part.
Assembly
Assembly is needed if a part is produced in smaller units that must be pieced together to form a larger product. During assembly, the workpiece is bonded together with other parts to form the final product. Bonding procedures or fasteners may be used to fuse parts permanently or temporarily.
Drilling
Drilling adds a round hole to a part. Drill presses, tapping, or a milling machine may be used to drill. Different types of drills may be used including peck drills or spotting, depending on the type of mark required.
Deburring
Deburring removes raised edges or burrs from a part. Electrochemical deburring, thermal deburring or abrasive flow deburring may be used to deburr a part. Electrochemical deburring uses an anodic metal dissolution to remove unwanted material. Thermal deburring uses a combustible gas in a pressurized chamber to deburr a part. Abrasive deburring uses an abrasive slurry to deburr the part.
Why Choose Fathom’s Wire EDM Services?
Accelerate Your Project with Wire EDM Cutting by Fathom
The Fathom team has extensive experience cutting parts with wire EDM and getting the highest quality results.
Our Tempe location is one of the premier shops for wire EDM services in the U.S. and has been producing parts using this technology for over 20 years.
We do wire EDM cutting for customers in a variety of industries, including automotive, medical, aerospace, satellite, solar and firearms.
Our wire EDM service has the capacity to handle your sheet metal fabrication and prototyping needs, large or small.
Contact us for your wire EDM quote today!