Why are Metal Disintegrators Sometimes Called Spark Eroders?

Spark erosion is the process of vaporizing metal using a high-frequency spark discharge.  Metal disintegrators are a subcategory of EDM, which is often referred to as Spark Erosion.  Metal Disintegration Machining  (MDM) is the process that Electro Arc machines use.  These machines are specifically used to remove broken bolts, taps, pins, screws etc. quickly      

"Spark Erosion" Applications:

Electro Arc Patented the Metal Disintegrator in 1942

If you are dealing with a broken screw, broken bolt, broken drill, or other broken tooling on a regular basis, you may have used a metal disintegrator to remove them.  Metal disintegrators are specialized EDM machines originally patented in 1942 by Electro Arc.   This broken bolt removal tool is essential in industries such as power generation, off-road vehicles, mining, aircraft repair, and automotive repair.

Remove your Broken Tooling wwth Metal Disintegration Machining

Spark eroders use the process of spark erosion, also referred to as spark machining, or die sinking to remove material from a part with electrical discharges.  This modern machining process is responsible for many of the manufactured processes that exist today. Electrical discharge machining (EDM) has a long history which has led to significant breakthroughs in technology. While EDM has a variety of applications, MDM has the targeted ability to remove broken bolts, broken pins, broken drills, and other broken tooling in minutes. Although metal disintegrators are in a sub-category of Electrical Discharge Machining called  Metal Disintegration Machining, the process is still considered spark erosion, hence the name spark eroder.  Part of this name has to do with the sparks that are created by this process, erosion obviously refers to the process which allows broken tooling to be removed with these machines.  The term spark erosion is more popular in countries like England and India. This term is used because the principal is more commonly understood under this name than “metal disintegrator”.  

In fact, Electro Arc used the term to refer to our own machines between 2008 and 2018.  Uni-Tek had a patent on the name “Tap-Zapper” which became associated with many of these machines as well.  Electro Arc kept the patent for a short time but also used the term to describe many of our AC metal disintegrating machines.  We find that these terms can be confusing and have made an effort to clarify each machine’s model and its features to help you choose the best metal disintegrator for your application.

Setting the Record Straight With Metal Disintegration Machining | Terminology

In the industry of metal disintegration machining, oftentimes there is misinformation about the terminology that is used to describe the machines, parts, and processes. We at Electro Arc Manufacturing are here to show you what is what when it comes to metal disintegration. Below are terms and proper definitions for processes and machinery-related items in the world of metal disintegration.  People in different areas use different terms to refer to our machine process. Some are misleading.  For our process, a real arc is essential. We don’t burn the material; we vaporize it to turn it into particles.

EDM is the correct term for a very different process. Electric Discharge Machining is much more precise than arc disintegration but also very slow. EDM machines are also MUCH more expensive. On the other hand, “MDM” stands for Metal Disintegration Machine, which is what we build. Terms like “spark eroder, spark erosion, spark burner, or spark disintegrator” are misleading and incorrect. Aside from superficial campfire embers, sparks are relatively low-power, momentary electrical effects like those in automotive spark plugs to ignite fuel. By contrast, our arc is a powerful current path operating at very high temperatures like in carbon-arc searchlights. Our arc process literally vaporizes the metal to be removed in a controlled way.
Metal Disintegration Machining (MDM)

Metal Disintegrators or MDM machines are manufactured for the specific purpose of removing broken tools from workpieces. The metal disintegration process removes a tap, bolt, or drill leaving the hole intact and allowing a part to be reclaimed.  MDM removes material very fast. MDM uses a spark erosion process commonly used for destructive cutting. Typical application includes broken tool extraction (taps, drills, reamers, drill bits) metallurgical sample excavation, and bolt removal. There is no faster or efficient or cost-effective method to remove broken tools, studs, or fasteners than MDM.

 

Electrical discharge machining (EDM), also known as spark machining, spark eroding, die sinking, wire burning or wire erosion, is a manufacturing process whereby a desired shape is obtained by using electrical discharges (sparks). Material is removed from the workpiece by a series of rapidly recurring current discharges between two electrodes, separated by a dielectric liquid and subject to an electric voltage. One of the electrodes is called the tool-electrode, or simply the “tool” or “electrode,” while the other is called the workpiece-electrode, or “workpiece.” The process depends upon the tool and workpiece not making actual contact.  When the voltage between the two electrodes is increased, the intensity of the electric field in the volume between the electrodes becomes greater than the strength of the dielectric (at least in some places), which breaks down, allowing current to flow between the two electrodes. This phenomenon is the same as the breakdown of a capacitor (condenser) (see also breakdown voltage). As a result, the material is removed from the electrodes. Once the current stops (or is stopped, depending on the type of generator), the new liquid dielectric is usually conveyed into the inter-electrode volume, enabling the solid particles (debris) to be carried away and the insulating properties of the dielectric to be restored. Adding new liquid dielectric in the inter-electrode volume is commonly referred to as “flushing.” Also, after a current flow, the difference of potential between the electrodes is restored to what it was before the breakdown so that a new liquid dielectric breakdown can occur.

Spark Erosion

Spark erosion is sometimes miscommunicated as being metal disintegrating but it is not. Spark erosion is a form of EDM or electric discharge machining that is a machining technique principally used for hard metals and metals that are difficult to machine using traditional methods. EDM normally operates with materials that are electrically conductive and is designed to erode (remove) intricate depressions or contours from pre-hardened steel negating the requirement for heat treatment to soften and re-harden the steel. We use this method on many different types of metals and alloys, such as Monel, Titanium, Tool Steel, Tungsten Carbide, Tantalum, Super Duplex, and Inconel.

Learn more about the spark erosion process.

Spark Eroder, Spark Burner, or  Spark Disintegrator (You may have heard these referred to as Metal Disintegrators)

Our metal disintegrators are sometimes referred to as Spark Eroders. This is a common term used throughout the UK. However, spark eroders produce sparks in the application, and metal disintegrators do not. So spark eroders are the machines that are used in the electric discharge machining field.

Metal Disintegrator

Metal disintegrators are primarily used for bolt removal, tap removal, stud removal, drill removal, and seized or broken bolts. The process can also be used for roll marking or branding for rebar identification, tool and die work, and metallurgical core sampling. The cutting action of a metal disintegrator is accomplished by creating a series of intermittent electric arcs that break down the hardest metals into minute particles. An electrode, held in the head of the disintegrator, vibrates as it cuts while coolant is pumped through the electrode to wash away the powdered metal.

Metal disintegrators or Metal Disintegration Machining (May be abbreviated as MDM in the machining industry) are primarily used for bolt removal, tap removal, stud removal, drill removal, and seized or broken bolts. Other terms used to describe these machines include bolt eater, tap zapper, and stud buster.
 
What is the Spark Erosion Process?

Imagine you’re on the production line working on a large manufacturing machine. Everything seems to be running smoothly, until crack, a tap has broken off in the machine. A person breaks the tap, not the machine.

Unable to retrieve the broken piece without damaging the machine or stripping the threads of the casting, you are left with two options. You can replace the broken machinery, which comes at a high cost and slows productivity, or you can apply spark erosion, solving your problem in seconds rather than hours or days and for a quarter of the cost.

Spark erosion, metal disintegration, electrical discharge machining; if you work in any industry that utilizes machinery you’ve probably heard one or more of these terms. Each of these titles is used to explain the process of removing metal using electric currents under carefully controlled conditions.

How does the spark erosion process work?

While (EDM) spark erosion can be used to create specific metal parts, it is also commonly used to remove broken drill bits, taps, bolts, and studs from within a machine casting without damaging the threads or casting itself. This is called MDM.

Spark erosion is conducted through metal disintegration machines (EDM). These machines use electrodes to send low voltage/ high current electrical charges that melts the designated piece of metal at the same time cold water thermal shocks the molten steel and pulverizes it into micro-size pieces and flushes it away.

Because there is no direct contact between the electrodes and the machine casting, spark erosion allows you to work with even the most intricate sections and weak materials without risking distortion. It is this precision that makes spark erosion the most effective way to salvage parts that would otherwise be deemed unusable.

Five steps to applying spark erosion

Step 1: Get your metal disintegration machine ready. Electro Arc has a variety of options to choose from depending on your need, including portable, table top, and specialized metal disintegrators.  Use our new Machine Builder if you are not sure which machine is best for your application.

Step 2: If you are using a portable machine, attach the provided portable electrode head to your drill press, CNC machine, lath, or any type of machine tool.

Step 3: Align the electrode to ensure it’s centered over the object you plan to remove and lower the splash bag.  Verify that the bolts are tight. Each machine comes with a splashguard mechanism for safety purposes in order to keep sparks contained and prevent eroded metal from flying.

Step 4: Switch on the power supply. Portable metal disintegrators come with a small, rolling power supply cabinet that is easily transportable. The power supply features a built-in coolant tank and heat selector knob. For easy usability, all machines come with a chart that directs you on exactly which heat setting to use for each size broken tap or drill that you’re planning to remove.

Step 5: Turn the heat selector knob to the desired temperature and begin the process. Within seconds, the MDM machine will finish its cut. You can then clear the hole of any remaining debris using the provided air compression tool and see that your part has been completely recovered, casting, and threads left unscathed.

Yo can see the Electro Arc process in action, with video tutorials and case studies on Electro Arc’s YouTube Channel.  Since Stillion Industries purchased Electro Arc in 2019, we have created a new channel with updated videos as well.

Advantages of using spark erosion machines

In a previous blog post, we discussed the many benefits of using Electro Arc’s spark erosion machines, some of which include:

  •      Simple operation
  •      Unbeatable price
  •      Relatively lightweight and easy to maneuver
  •      Quick setup and breakdown
  •      Easily manageable for one person
  •      Little-to-no maintenance; simply keep it filled with fresh coolant

Spark erosion is the fastest and most cost-effective solution to recovering machinery that has been compromised by broken tools. For 75 years, Electro Arc has been perfecting this process and supplying premium metal disintegrators at affordable prices throughout the world.

You can see lots of broken bolt removal examples which illustrate how an Electro Arc metal disintegrator will benefit your company and save you money.

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