• Virtual Showroom
  • Your Sodick
  • Careers
  • Locations
  • About
  • English
    English Spanish
Get a Quote

TL;DR

Automatic wire threading is the difference between a machine that runs overnight and one that waits for morning. When the wire breaks mid-program, the machine rethreads and keeps cutting instead of sitting idle until someone walks over to it.

If you are shopping for a reliable wire EDM machine with automatic wire threading, the thing to know early is that it works differently from one machine to the next. Threading by hand means emptying the tank before an operator can touch the wire. On a material that breaks wire repeatedly, that repeats every time. Submerged threading skips the sequence.

Sodick’s two submerged systems, Fixed Jet and Super Jet, both thread with the tank full. The difference between them is how each one prepares the wire first. Fixed Jet cuts the wire thermally so it comes away straight, then uses a water jet to carry it through the workpiece. Super Jet does the same and adds an annealing step, heating and stretching the wire before cutting it to a sharp point. An annealed, pointed wire holds its line across a longer unsupported span, which is why Super Jet is matched to tall parts and steep tapers while Fixed Jet is matched to shops restarting constantly across a wide job mix.

Why Automatic Wire Threading Determines Your Uptime Ceiling

Without submerged threading, a wire break means:

  1. Drain the work tank
  2. Raise the table
  3. Rethread the wire
  4. Lower the table
  5. Refill the tank
  6. Wait for the dielectric to stabilize before resuming a precision cut

With submerged threading, a wire break means: the machine rethreads and keeps cutting.

Every step in that first list needs an operator standing at the machine. On an overnight run, none of it happens until someone arrives in the morning, which is why a break at midnight can cost a full shift rather than a few minutes. On a material that breaks wire repeatedly, the sequence repeats on every break.

Sodick’s Fixed Jet and Super Jet at a Glance 

Fixed JetSuper Jet
Full nameFJ (Fixed Jet) High Speed AWTSuper Jet Annealing High Speed AWT
Standard onALN iGE+, ALP iGE+, and VN Series + AX350LAQ and AP Series
Wire preparationThermal cut, producing a straighter wireAnnealed, then cut to a sharp point
Threading aidWater-jet functionWater-jet function, plus sensor-monitored tension feedback
Submerged threadingYes, with unsubmerged capabilitiesYes, tank stays full
Pairs withClosed guides, which further increase productivityWire guides, plus automatic dielectric fluid level setting
Design priorityFast, repeatable restarts across a high job mixThreading repeatability at larger Z heights

How Fixed Jet Automatic Wire Threading Works

FJ (Fixed Jet) High Speed AWT is our automatic wire threader. It comes standard on the ALC-G Series, the ALN iGE+ Series, the VN Series, and the AX350L.

Fixed Jet is a combined system rather than a standalone threader. It pairs the automatic threading mechanism with the wire guides themselves, and the two work together. Thermal wire cutting and a controlled water jet handle the threading. Closed guides handle the wire capture at either end. The exclusive use of closed guides in combination with the FJ AWT further increases productivity, which is the whole design premise.

Submerged Threading

Fixed Jet threads in both submerged and non-submerged conditions. When the wire breaks, the tank stays up and the machine rethreads where it is, which is what lets an overnight run recover with nobody present.

Closed Guides Multiply the Effect

On machines like the ALN800G iGE+, closed guides are used throughout.

A closed guide captures the wire more completely and more repeatably than an open guide, which means tighter positional control at the moment the threader is trying to land the wire.

How Super Jet Automatic Wire Threading Serves Tall Parts and Extreme Tapers

Our Super Jet Annealing High Speed AWT works the same way Fixed Jet does, with one addition. It threads automatically and threads submerged, working with the wire guides the same way Fixed Jet does. The addition is an annealing step that prepares the wire before threading begins. Super Jet comes standard on our large work area and extreme taper machines, and can be specified on others

How Annealing Changes the Wire

Annealing improves wire straightness, which increases AWT repeatability. The gain is largest at bigger Z heights. A wire that crosses a long unsupported span has more room to wander, and a straighter wire holds its line.

During annealing, the wire is heated and stretched. It is then cut to a sharp point rather than simply parted. A pointed tip requires less wire guide clearance than a blunt one, which improves part accuracy on top of the threading gain.

A sensor in the wire traveling system monitors tensile force and feeds that data back to hold the optimum condition throughout the run.

The annealing AWT threads in submerged mode as well, so the worktank stays full during a rethread, and the Z axis position sets the dielectric fluid level for the operator automatically.

Threading and Tension Through Extreme Tapers and Thick Workpieces

Extreme taper compounds every threading variable. A sample part we cut on the AQ900L runs NAK55 at 7.874 inches thick with a 30 degree taper angle, cut with 0.01 inch wire. On geometry like that, the wire travels a long angled path and lands in a guide offset by the U and V axes.

With Super Jet AWT, tension stability is the other half of the problem. Wire tension is measured just prior to the wire entering the cutting zone, and all adjustments are made automatically at that point. That eliminates tension variation caused by taper cutting. It also removes variation from changing spool sizes, which otherwise accumulates across a long unattended run.

Matching Automatic Wire Threading Technology to Your Part Mix

Find your work below.

  1. High-mix precision work, mostly under 20 inches of Z, where you need fast repeatable restarts across many setups. Look at the ALP iGE+ or ALN iGE+ Series with Fixed Jet. Submerged threading paired with automatic fluid level control unlocks unattended running for this profile
  2. Tall parts with steep tapers, or heavy workpieces. Look at the AQ Series with Super Jet. The annealing step is what holds threading repeatability as Z height increases.
  3. Proven linear motor performance on a tighter capital budget. Look at the VN600Q, which includes Fixed Jet and an improved surface finish circuit. You keep the threader at the lower price point.
  4. Cemented carbide work with cobalt depletion concerns, or an oil dielectric requirement. Look at the AP Series, which runs the same Super Jet threader on a fine wire platform. The oil dielectric AP250L machines carbide while eliminating cobalt depletion.

Three Questions to Ask Any EDM Vendor About Threading

Whatever you end up buying, ask these before you sign.

1. Can it rethread submerged, with the tank still up? If the answer involves any version of “it depends,” you have found a limitation that will cost you hours every month. Ask for a demo on a part rather than a bare table.

2. What happens when it has to thread a start hole at maximum Z? Rethreading into an existing kerf is the easy case. Threading a start hole at full Z height is the hard case, and it determines whether your tall work can run unattended. Make them answer for the hard case.

3. Is the threader standard or an option? Then ask what the closed guides cost. A base price with an uptime-critical feature list hanging off it is an incomplete quote.

Threading Is Only Half the Equation

Threading is the first constraint on unattended running. A few others decide whether the program finishes.

Standard equipment on the machines in this article:

  1. Automatic wire tension servo control and automatic voltage regulator. Long cycles expose instability that a short job would hide. Both hold conditions steady across the full run.
  2. Dielectric cooling, plus three-part filtration on our ALP iGE+ and ALN iGE+ machines. Dielectric condition drifts as you cut. Active cooling and filtration keep flushing and thermal conditions consistent from the first hour to the last.
  3. Z-axis automatic fluid level control. Fluid level follows workpiece thickness without an operator setting it.
  4. Thermal Commit (TH COM). Component temperatures are sensed and corrected to minimize thermal displacement from changes in the installation environment and from high-speed driving. On an overnight run in a shop where the HVAC cycles down, that correction is doing steady work in the background.
  5. iGroove+ wire rotation. Our patented wire rotation technology improves surface quality and accuracy while reducing wire consumption by up to 30 percent.

Available as options worth specifying if unattended running is the goal:

  1. Jumbo wire feeders. A 44 pound integrated spool or a 110 pound feeder means wire supply stops being the thing that ends your weekend run.
  2. L-Cut wire chopper. Processes wire for convenient storage, which keeps waste handling from requiring an operator.

We back our flat rigid linear motor driven wire and sinker EDMs with a 10-Year Positioning Accuracy Guarantee, plus a 2-year standard warranty and SodickCare +2 or +4 extended coverage. The drives eliminate backlash and have zero contact, enabling us to guarantee positioning accuracy for a decade after purchase.

If threading reliability is the first step toward unattended machining, automation is the next one. Single and dual machine solutions supply palletized material and tooling without custom configuration.

Maximize Your Uptime with Automatic Wire Threading

If you want to know which threading system fits your part mix, we can help. Tell us about your typical thickness and taper requirements, along with the unattended hours you are trying to capture. Connect with a Sodick expert and we will walk you through what machine and which AWT matches your job.

Wire EDM has been around since the 1960s, and for the first few decades, non-submerged machining was simply how it was done. The workpiece sat above the fluid line, and two nozzles, one above, one below, sprayed deionized deionized water around the wire to create the dielectric environment needed to cut. It was the only option available, so operators learned to work with it, quirks and all.

Things started to change in the 1980s and 1990s as submerged machining technology matured. Manufacturers began developing tanks that could fully immerse the workpiece, surrounding the entire cut zone in dielectric fluid. The performance advantages were immediately obvious: faster cutting, more stable sparks, less wire breakage, better surface finishes. Shops that made the switch didn’t go back.

Today, non-submerged wire EDM is largely a relic of the past. The last major manufacturer of dedicated non-submerged machines exited the market years ago. Modern machines are built around submerged operation — and for good reason. This article breaks down exactly why submerged machining won out, how the two methods compare head-to-head, and how dielectric oil takes submerged performance into territory that deionized water simply can’t reach.

Why Non-Submerged Machining Became Obsolete

To appreciate the advantages of submerged machining, it helps to understand what operators were actually dealing with on non-submerged machines; it was a fundamentally more difficult process to control.

The Fluid Problem

In a non-submerged setup, dielectric fluid is delivered through upper and lower nozzles that spray deionized water around the wire entry and exit points. The goal was to achieve what machinists called an “umbrella”; a cone-shaped flow of deionized water that kept the spark zone wet while the workpiece sat exposed to air. Getting there required careful balancing of nozzle pressure and position, all at extremely low power settings.

If you got it wrong, you knew immediately. Red sparks — a visible sign that the discharge environment was breaking down due to inadequate flushing — would appear, followed quickly by wire breakage. Some operators wrapped neck strips around the machine head and held them in place with clothespins to help seal the nozzles against the workpiece. It worked, but it was a workaround that revealed a fundamental limitation of the process. The machine was fighting you at every step.

Thermal Instability

Beyond the flushing challenges, non-submerged machining created significant thermal management problems. With only the nozzle spray cooling the workpiece, heat distribution across the part was inconsistent. The area being cut might be adequately cooled, but adjacent areas of the workpiece were exposed to ambient air, creating temperature gradients that caused dimensional drift; particularly problematic on longer cuts or when holding tight tolerances.

In a submerged setup, the fluid surrounding the entire part acts as a thermal buffer, absorbing and distributing heat evenly. This consistency is one of the key reasons submerged machining can hold tighter tolerances with less operator intervention.

Constant Operator Attention

Non-submerged machining demanded presence. Operators had to monitor the umbrella effect continuously, watch spark color, manage power ramp-up carefully, and respond quickly when anything went wrong. Unattended operation, let alone lights-out machining, was essentially off the table. The process simply wasn’t stable enough to run without supervision.

Submerged machining changed the equation entirely. With the fluid environment already established before the cut begins, the machine can run at full power settings from the start, with far fewer interruptions, and less babysitting required.

Head-to-Head — Where Submerged Wins Every Time

The performance gap between submerged and non-submerged wire EDM shows up across every meaningful metric. Here’s how the two methods compare directly.

Comparison Overview

FactorNon-SubmergedSubmerged
Startup timeSlow — requires low-power ramp-up to establish umbrellaFast — full power from the start
Cycle timeLonger — conservative power settings throughoutShorter — higher power, more aggressive cutting
Surface finishInconsistent — flushing variability affects finish qualityConsistent — 7.5 Ra achievable with 1 rough + 7 skim passes
Cutting stabilityProne to wire breakage and spark instabilityStable spark environment throughout the operation
Thermal controlInconsistent — partial cooling creates dimensional driftEven — full immersion buffers heat across the entire part
Operator burdenHigh — continuous monitoring requiredLow — machine handles process autonomously
Lights-out capabilityNot viableFully supported

Job Run Time

The cycle time difference starts before the first spark even fires. In a non-submerged setup, reaching stable cutting conditions requires starting at minimal power and patiently waiting for the umbrella to form and the nozzles to seat properly. Power can only be increased gradually, and a wrong move means wire breakage and a restart.

Submerged machines skip all of that. The tank fills, the part is immersed, and the machine cuts at optimal power settings from the first pass. There’s no ramp-up, no umbrella to find, no spark color to monitor. That difference adds up significantly across a full production run, and compounds even further when reduced wire breakage and fewer interrupted cuts is factored in.

Surface Finish and Precision

Cutting consistency directly drives surface quality, and nothing creates consistency like full immersion. In a submerged environment, every pass of the wire happens in the same controlled fluid environment, with the same flushing effectiveness, the same thermal conditions, and the same spark characteristics. The result is predictable, repeatable surface finishes cut after cut.

On Sodick’s deionized water-based wire EDM machines, operators regularly achieve 7.5 Ra with a single rough cut followed by up to seven skim passes — smooth enough that, at the right angle in the light, you can see a reflection in the part surface. Non-submerged machining, by contrast, introduces variables into every pass: localized flushing variations, temperature differentials, and spark instability that all leave their mark on the finished surface.

Cutting Consistency and Stability

Wire breakage is the single biggest source of unplanned downtime in wire EDM. On non-submerged machines, the conditions that cause wire breakage — inadequate flushing, unstable spark environment, thermal stress on the wire — are baked into the process. Even experienced operators couldn’t eliminate them entirely, only manage them.

Submerged machining dramatically reduces breakage frequency. The wire cuts through a consistent fluid environment on every pass, with reliable flushing and controlled spark intensity. Less breakage means less downtime, fewer resets, and lower risk of surface damage on nearly finished parts. It also results in fewer situations where secondary machining is needed to correct for inconsistencies introduced mid-cut.

Dielectric Oil — When Submerged Machining Needs to Go Further

Deionized water-based submerged machining covers the vast majority of wire EDM work. But for ultra-precision applications and micromachining, dielectric oil fluid unlocks a level of precision that deionized water simply can’t deliver.

Oil-based wire EDM is best understood as the next evolution of submerged machining rather than a separate method. The workpiece is still fully immersed. The process still relies on controlled electrical discharge. But, the dielectric properties of oil change the spark dynamics and make ultra-precision on the first pass possible.

Smaller Spark Gap, Finer Detail

The lower electrical conductivity of oil compared to deionized water creates a smaller discharge gap between the wire and workpiece. A smaller gap means the spark is more precisely localized, which translates directly into finer feature resolution and tighter dimensional control. For parts with intricate geometry, narrow slots, or microscopic features, this distinction is the difference between achievable and not achievable.

Sodick’s AP350L, for example, is purpose-built for fine wire micro machining with dielectric oil, achieving cutting accuracy down to 2 microns; the kind of tolerance that requires specialized measurement equipment just to verify.

Cobalt Depletion Eliminated

Machining carbide with deionized water dielectric causes a well-documented problem: the electrolytic reaction between deionized water and the cobalt binder in carbide gradually depletes cobalt from the workpiece surface, weakening the material and compromising part integrity. This is a critical limitation for tool and die shops working with carbide on a regular basis.

Dielectric oil eliminates this problem entirely. Without deionized water, there’s no electrolysis, no cobalt depletion, and no degradation of the carbide binder. The workpiece comes out with its material properties fully intact — a non-negotiable requirement for high-performance tooling applications.

Ideal for Medical Device Components

Medical device manufacturing represents one of the most demanding application environments in precision machining. Components are often microscopic, features are intricate, tolerances are measured in microns, and there is no margin for error on parts destined for surgical or implantable use.

Dielectric oil submerged wire EDM is built for exactly this work. The smaller spark gap enables feature resolution that deionized water-based machines can’t match. The stable, controlled cutting environment produces the surface consistency that medical manufacturing requires. And because oil doesn’t corrode metal the way deionized water does, finished parts can remain in the tank for extended periods without any risk of surface degradation — critical for shops running lights-out operations where parts may sit overnight before retrieval.

Lights-Out Machining Without Corrosion Risk

With deionized water dielectric, finished parts need to come out of the tank promptly after machining completes. Deionized water causes corrosion on ferrous materials, and leaving a part submerged after the cut is finished risks surface damage that can compromise part quality or require additional finishing.

Oil carries no such risk. A carbide workpiece can remain in an dielectric oil tank for extended periods, nights, weekends, however long, without any corrosion concern. For shops that run unattended overnight shifts, this isn’t a minor convenience. It’s a meaningful operational advantage that expands what lights-out machining can realistically accomplish.

Eco-Cut O: Oil Speed Without the Oil Penalty

One of the historical trade-offs with dielectric oil has been speed. Oil-based machines have traditionally cut slower than deionized water-based machines; a worthwhile trade-off for ultra-precision work, but a real limitation in high-production environments.

Sodick’s Eco-Cut O technology, available on the AP250L, directly addresses this trade-off. Eco-Cut O achieves the surface finish and precision advantages of dielectric oil while cutting up to 12% faster than deionized water dielectric and up to 25% faster than conventional dielectric oil. It speeds up the cutting process by reaching the required accuracy and surface finish in fewer passes — delivering oil-quality results without the penalty of traditional speed.

Sodick Technology Built for Submerged Performance

Whether you’re running deionized water or dielectric oil, Sodick’s wire EDM platform is engineered to extract maximum performance from a fully submerged process.

3-Sided Rise/Fall Worktank automatically adjusts fluid level based on workpiece thickness, eliminating manual fluid management between jobs. The no-drip design keeps the shop floor clean, and the tank can pause at intermediate positions to check progress on thinner workpieces without a full drain.

Fixed Jet Automatic Wire Threader (FJ AWT) supports both submerged and non-submerged threading. Thermal wire cutting produces a straighter wire tip, and the deionized water-jet function improves threading reliability — getting the machine back in cut faster after breaks.

iGroove+ Technology — Sodick’s patented wire rotation system — improves surface quality and accuracy while reducing wire consumption by up to 39%. In high-production environments, that’s a direct reduction in operating cost.

Thermal Commit (TH COM) monitors the temperature of every machine component and compensates in real time, minimizing dimensional variation caused by ambient temperature changes or extended high-speed operation.

All of this runs on Sodick’s flat rigid linear motor drives — no belts, no ball screws, no backlash — backed by the industry’s only 10-Year Positioning Accuracy Guarantee. Tolerances of ±.0001″ are held reliably, year after year, across the full service life of the machine.

The Bottom Line

Non-submerged wire EDM had its era. For the operators who mastered it, it was a legitimate skill. However, the industry evolved, and the machines that replaced it weren’t just incrementally better, they were a different class of process entirely. Submerged machining delivers faster cycle times, better surface finishes, more consistent cuts, and dramatically lower operator burden. 

And, for the applications that push beyond the capabilities of deionized water dielectric, oil-based submerged wire EDM, particularly with Eco-Cut O technology, opens up a tier of precision that was previously unattainable for most. Micro-components, carbide tooling, medical device parts measured in microns: this is where the industry is heading, and Sodick is leading the charge, spearheading this next evolution.Whether you’re evaluating your first wire EDM machine or looking to upgrade, connect with a Sodick expert today to find out which machine fits your operation.

EDM wire is a critical part of the EDM process, directly influencing cut stability, speed, and surface finish. The type of wire used affects how consistently the cut performs, how efficiently material is removed, and how reliable the process is over time.

This is a comprehensive guide that breaks down the most common wire types used in EDM applications, explains when each is typically used, and answers common questions around cutting hardened materials and wire reuse. The goal is to provide a clear, practical foundation, so you can choose the right EDM wire for your application with confidence.

Why EDM Wire Selection Matters

EDM wire is the electrode that makes the entire process possible. Every electrical discharge that removes material happens between the EDM wire and the workpiece, which means the wire’s behavior directly influences how smoothly and efficiently the cut happens.

The right EDM wire can help:

Using a wire that doesn’t match the application can lead to slower cycle times, inconsistent results, or unnecessary downtime. That’s why wire selection should always be tied to the job at hand, not just price alone.

What Wire Is Used for EDM? A High-Level Breakdown

So, what wire is used for EDM most often?

EDM wire generally falls into three main categories:

While there are many variations within each category, most Wire EDM applications rely heavily on brass and coated wires. Specialty wires exist for niche needs, but aren’t suited for most shops or most jobs. 

Understanding Brass EDM Wire: The Industry Standard

Brass wire is by far the most commonly used wire in the EDM industry, and for good reason.

Brass offers a reliable balance of:

Most brass EDM wire is made from a copper-zinc alloy. Sodick’s brass wire uses a 60/40 ratio, 60% copper and 40% zinc, specifically engineered for optimal performance on Japanese-manufactured machines like Sodick’s Wire EDMs. This higher zinc content delivers better cutting performance on machines designed around this composition, though other manufacturers may use different ratios such as 65% copper and 35% zinc.

One key characteristic you’ll often hear about with brass wire is tensile strength. Tensile strength affects how stiff or flexible the wire is during cutting:

For example, when cutting tapers or parts with varying geometry, a softer wire may be less prone to unwanted bending effects. On the other hand, straight, high-precision cuts often benefit from a stiffer wire that maintains alignment.

For many shops, especially those running general-purpose jobs, brass wire is the go-to choice because it performs well across a wide range of materials and applications without significantly increasing operating costs.

When and Why to Use Coated (Gamma Phase) EDM Wire

Coated wire helps production shops gain efficiency when cutting the same job repeatedly in high volumes. 

Wire EDM coated wires were developed to push performance beyond what standard brass wire could deliver. These wires typically start with a brass core and then receive a surface coating, often zinc-based, through controlled manufacturing processes.

So what does that coating do?

In simple terms, coated wires can:

In production environments where the same part is cut repeatedly, cycle time matters. Coated wires can deliver 10-30% improvements in cutting efficiency compared to brass wire. While coated wire typically costs about $1 more per pound than brass, this performance gain often justifies the investment—especially in high-volume production where increased throughput translates directly to profitability.

Coated wire is also useful when flushing conditions aren’t ideal. For example, if the upper and lower heads can’t be positioned close to the workpiece, debris removal becomes more difficult. Coated wire can help maintain a stable cut in those less-than-perfect setups.

In short, coated wire isn’t about replacing brass wire everywhere, it’s about using the right tool when performance demands it.

Specialty EDM Wire: Application-Driven Options

In some cases, standard brass or coated EDM wire may not be the best fit. That’s where specialty EDM wire comes into play.

Specialty wires are designed for ultra-precision applications that demand exceptional accuracy. In aerospace manufacturing, these wires cut microscopic holes in critical components. In the medical field, they create surgical instruments designed to fit inside blood vessels—parts so small they can only be inspected under a microscope. While specialty wires represent a small percentage of EDM jobs, they’re essential for applications where precision cannot be compromised. 

These wire types are not intended for general use. Instead, they are selected when cutting conditions push beyond what standard EDM wire can reliably handle. They typically cost four to six times more than standard brass wire, but for applications requiring microscopic precision and FDA approval, they’re non-negotiable. 

Can EDM Wire Cut Hardened Steel?

Yes — EDM wire can cut hardened steel, and it’s one of the reasons EDM is so valuable in precision manufacturing.

Because the process relies on electrical discharge rather than mechanical force, material hardness has very little impact on cut capability. EDM wire can be used to machine:

This allows shops to cut parts after heat treatment, helping maintain accuracy and eliminate distortion that can occur with traditional machining methods. While brass wire can handle hardened materials, coated wire is often the better choice for cutting hardened steel. 

Can EDM Wire Be Reused?

In most cases, EDM wire cannot be reused.

During cutting, the wire is exposed to continuous electrical discharges and thermal stress. Even if it appears intact, the wire’s surface and electrical characteristics change as it’s used.

Reusing EDM wire can lead to:

For that reason, EDM wire is designed as a single-use consumable. The cost of fresh wire is minimal compared to the potential cost of scrap parts or machine downtime.

Find the Optimal Wire for Your Job

If you have questions about EDM wire selection, application-specific challenges, or how to optimize your consumables program, connect with an expert today. Our team can help you evaluate your wire needs and identify solutions that support accuracy, efficiency, and long-term cost-effectiveness.

EDM (or electrical discharge) machines are one of the most popular CNC machine tools around. They belong to the class of machines capable of starting with raw material, like a block of steel, and making very complex parts with precise tolerances and amazing repeatability.

EDM machines are used for many different types of metal fabrication and for cutting various materials from soft iron alloys to steels. The EDM process itself is relatively straightforward, but there are things to consider before deciding if an EDM machine is suitable for your shop or business.

EDM machines work by using electricity to cut metal

EDM is a common machining method often reserved for difficult-to-machine materials such as hardened steels and superalloys. It’s used to produce parts from these materials when conventional methods are too costly or impractical.

EDM machines use electricity to cut metal by plasma cutting, which involves a thin wire being charged with electricity and placed into a spool called an electrode. The wire is then fed through the spool to discharge into whatever material needs cutting—plastic or steel.

The EDM process relies on an electrical charge to create a spark that cuts metal. To do this, the machine uses electrodes or metal parts with wires coming out of them.

The electrodes are placed in a cutting fluid and connected to an electrical power source, usually a standard outlet. EDM works by placing the workpiece into an electrically conductive bath (called an electrolyte) which contains metal ions. When a small electrical current is passed through the electrolyte, it creates an electric field that attracts the negative ions in your material (i.e., iron). 

A high-voltage electrode will then create an arc between itself and your workpiece, removing those positive charges to make room for more negative ones on your part while simultaneously melting its surface layer. The result is a clean circular groove around its circumference where only solid material once existed.

Turning on the machine creates a circuit between the electrodes and the ground (called a “return”). To make sparks, electricity must flow from one electrode through the cutting fluid and back through another electrode so there’s a complete electrical circuit between them. This happens when you turn on your EDM machine: Electricity flows from one electrode through your workpiece (your metal piece) and back into another electrode so there’s now current going around two circular paths within the metal at once.

How fast do EDM machines operate?

EDM machines are some of the fastest machine tools in the world, capable of cutting up to 250 inches per minute. Many factors determine the speed at which an EDM machine operates:

The roles of the electrodes in the EDM process are reversed

In the EDM process, a positive electrode is replaced with a negative one and vice versa. This switches the roles of the electrodes in the EDM process. When an electric current passes through your motor, it generates heat. The heat causes carbon to melt, forming an arc between the wire and electrode. The melted carbon then floats away from its original location, where it creates your groove or whatever shape you’re trying to create in metal.

EDM cutting fluid, or dielectric fluid, serves several purposes during the process. It cools the workpiece to prevent thermal shock as it passes through the cutting zone. The dielectric fluid also cleans the surface of your workpiece, removing any dirt or debris on it.

If you were to look closely at a spark discharge between two wires, it would appear like they were burning off excess material from one wire onto another. If no dielectric fluid were present, this would happen immediately and cause damage to both wires (and possibly even damage to your machine). The dielectric fluid prevents this from creating an insulating barrier between the two wires until enough buildup has occurred for current flow through them to happen again.

Because the cutting wire never makes contact with the workpiece throughout the EDM process, no stresses are added to the component. As a result, less stress may be used for creating slots, grooves, and eyelets in machined items using EDM.

The coolant also lubricates both wires to move smoothly past each other without getting stuck together or overheating due to friction caused by poor lubrication. 

EDM’s superior finish is one of its additional advantages. With tight tolerances, the wire cutting process produces surfaces that are burr-free and smooth. In fact, wire EDM can be used to create through-slots and very thin eyelets for medical devices—features that are inaccessible to traditional centers.

How noisy are EDM machines when operated?

When comparing the noise level of an EDM machine to other machining methods, it’s essential to remember there are many different types of EDM machines on the market. Some are pretty loud, while others are much quieter. For example, you might think a plasma cutter would make a lot of noise because of all its sparks, but it’s significantly quieter than an electric motor running at full speed.

Similarly, although an EDM machine may use electricity for power instead of air pressure like with a milling machine or router bit (and therefore produce less heat), this doesn’t necessarily mean it’ll be quieter than these other options. It depends on how well built your particular unit is and what kind of material you’re working with; certain materials are naturally noisier than others when being cut into or drilled through (for example, metal tends to be louder than wood). In general, most EDMs tend not only to produce less heat but also require less airflow around them during operation, resulting in lower overall noise levels due to reduced air turbulence generated by their cutting action.

What are the maintenance requirements on an EDM machine?

EDM machines are more complicated than other machining methods, requiring more maintenance. There is a weekly, monthly and yearly maintenance recommendation. These recommendations are located in the machine tool’s manual which is supplied with the machine.

As part of operating an EDM machine, you’ll need to clean and lubricate it regularly. You may also have to inspect and maintain it regularly, as well as calibrate it from time to time. Sodick offers service and maintenance for the machines it sells. 

How (or when) is an EDM machine better than the alternatives?

Regarding precision, speed, and ease of use, EDM machines have few rivals. The machines allow you to create complex shapes—even ones that would be impossible by any other means.

As for what an EDM machine can’t do: They’re not good at cutting soft metals like aluminum or copper. However, they aren’t really meant for those materials anyway (in fact, most EDMs won’t even work on them).

It is best to consult a professional when deciding which machine is suitable for you. The variables involved in choosing an EDM machine include the material being cut, its hardness, and how much material to remove. Sodick is here to answer all of your questions.

A traditional machine shop has many different machines, some designed for a particular function, and others more adaptable. An electrical discharge machine, or EDM, might be the most important tool in a contemporary shop. Also known as a spark machining tool, an EDM machine cuts conductive materials using sparks or electricity. By eliminating material, it creates cuts using electrical energy.

EDMs present some comparatively innovative production technology, which is what makes them so unique. They utilize electricity to wear away at the metal, able to cut through any conductive material. There are several tasks in a machine shop where utilizing EDM is preferable to conventional machining techniques.

What is electrical discharge machining?

In electrical discharge machining, material is eroded using electrical energy. That energy generates a series of high-frequency sparks between an electrode made of copper, brass, graphite, or tungsten and alloys from each of those metals and an electrically conductive workpiece.

When the spark jumps from the electrode to the workpiece, the erosion process removes excess material from the work piece, which is then flushed away by dielectric fluid. The fluid is typically a specific non-conductive oil or deionized water. Extremely fine finishes, and accuracy down to the micron, are both possible.

EDM comes in three primary types: conventional, also known as “sinker,” EDM hole drills, and wire EDM, also known as “WEDM.” 

What is wire EDM?

In Wire Electrical Discharge Machining, or Wire-Cut EDM, a thin single-strand metal wire is fed through the work piece, typically occurring in a submerged dielectric fluid tank of deionized water. This fluid helps to cool the process and flush away the cut material. The Wire EDM process uses electric current to cut conductive materials, leaving a smooth surface that requires no further finishing or polishing.

This process is used to cut plates and to make punches, tools, dies, molds, and parts from any conductive material, including hard metals that are too difficult to machine with traditional methods (such as metal alloys, graphite, carbide and diamond). 

All this means that a Wire-Cut EDM can be programmed to cut very intricate and delicate shapes. There is little change in the mechanical properties of a material in Wire EDMing due to its low residual stresses.

What is EDM hole drilling?

There are several advantages and benefits to EDM small hole drilling.

What is sinker EDM?

In sinker EDM, a custom tool-electrode (often referred to as just the electrode) approaches the workpiece-electrode (often referred to as just the workpiece), and a series of sparks—referred to as EDM pulses—between the electrode and the workpiece remove material from the workpiece while the electrode machines the workpiece into the desired shape. 

Molds, die sets, and other parts are made with sinker EDM in a variety of industries, such as the medical, aerospace, and power generation sectors. 

When EDM machines are preferable to conventional machining methods

1. They can complete large jobs

Generally speaking, traditional machines are made to operate primarily in automated situations, but they require upkeep. On the other hand, EDM machines are less prone to errors or interruptions and thus may be left to operate with little supervision.

2. They’re amazingly accurate

Some traditional machines can’t be used in specific situations, such as when cutting sharp internal corners. For EDM machines, especially wire-based models, this is not the case. With the right kind of wire, tension, and feeding, it’s possible to cut interior corners that are sharp and tightly packed and ultimately produce designs that would not be feasible using other techniques. 

3. They’re capable of deep cuts

The materials frequently used in a machine shop are challenging to work with because they are so hard. This often meant developing designs that used shallow cuts to reduce the amount of effort required to make the cuts. EDM machines can make deeper cuts, even with very hard materials.

Additionally, such cuts won’t cause ineffective or problematic seams. In other words, regardless of how deep it must cut, the tool consistently produces a clean, dependable cut regardless of how strong the material. 

4. They create robust molds

Due to the technology’s ability to cut through solid materials, operators frequently choose EDM machines over standard CNC machining when creating molds. 

Sometimes, to make a mold, two machining methods will be employed—first, a CNC mill will be used to make the negative shape, and then a wire EDM will be used to make the edges more precise. This is an excellent method for creating an injection mold. Furthermore, because the finished mold materials are so much stronger, costs are reduced because they need to be replaced less frequently. However, it also opens up a more comprehensive range of possibilities than would be conceivable with delicate or one-use molds.

It is possible to completely rethink machining and production when the molds made by EDM are combined with additive manufacturing techniques.

5. They work best with hard materials

Many materials, including some of the toughest in the field, may be bored through and cut with EDM devices. Even when meeting strict standards, the toughness has little impact on precision or maneuverability.

An EDM tool can effectively cut all conductive materials including tungsten carbide, hardened steel, titanium, Inconel alloys, and even materials like Hastelloy, composed of nickel and molybdenum. It is nearly impossible to cut these materials accurately using conventional cutting and machining techniques.

6. They can design a distinctive finish

EDM tools can indeed create surfaces like craters and pockmarks depending on the speed of the cut; this is typically the case when cutting swiftly. This can be a benefit when altering different parameters. For instance, cutting at lower power minimizes flaws and yields a smoother surface with a mirror-like gloss.

Operators can make adjustments to enhance the completed product and cut down on extra stages. Other tools are not required to obtain the same result because you can attain that mirror-like finish. This helps provide excellent work while also accelerating overall output.

Better results are available with electrical discharge machining

EDM technology isn’t perfect for every case or application because it can’t be utilized to cut materials like plastic or plaster. But electrical discharge machining offers many advantages when it comes to hard conductive materials or metals.

Your company will gain from unmatched precision and the ability to make deeper cuts and produce more refined edges while encountering less resistance. EDM tools can operate as much as required, with no interaction, even in an automated “lights out” facility, because they are very reliable.

At the very least, there is no excuse for your machine shop not to have an electrical discharge machining tool (or a few) on your shop floor. Sodick is ready to help you assess your requirements.