Advantages of Wire EDM
Precision Cutting of Tough Metals

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

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.

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.)

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)

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 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 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 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 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.