Electro Arc

Category Metal Disintegration

Electro ARC’s New Tool for Metal Disintegrator owners

As Electro Arc machine owners, we understand that you need resources in addition to the owner’s manual you received with your metal disintegrator.  As a company that has been producing metal disintegrating machines for 75 years, we know we have quite a few versions of our product in use with various stages of support needed.

Since Stillion Industries purchased Electro Arc, we have been striving to improve both the product and the support offered for these machines.  Both of these processes are time-consuming and costly, so it has taken us a while to get to the point where we can produce new media to replace set-up and operation videos that are currently available.  We have been offering new content through our YouTube channel to address common questions and demonstrate how our machines work.

We recently released a 30-page troubleshooting guide which addresses the most common issues machine owners may have with their metal disintegrator or disintegrating head.  This guide is free of charge and is available for download in our store here on ElectroArc.com   You may have noticed that a majority of the content from our troubleshooting section has moved.  This is because we have created a new resource to assist existing machine owners.

We have also dedicated a new website to hosting all of the current setup and operation videos that we have for our metal disintegrators (yes, they are from the 90s) but they do cover the important points new machine owners may need to cover for training purposes.  This website Metal-disintegrators.com is dedicated to providing a resource for machine owners through multi-media.  We will continue to expand and improve the content available on this site.

Comparing Electro Arc disintegrating heads

Electro Arc’s Arc-er portable disintegrating head

Arc-er Head in action

The Arc-er head is ideal for portable use. You can use it with portable or tabletop metal disintegrators. You can also use the Arc-er head with machine tools like CNC machines, Bridgeport, Radial drill, lathe or mill, and directly on the workpiece. This head operates at any angle. You can remove broken tooling from .079 to 3/4 inches in a single pass.

The Arc-er head is standard with the following machines:


In September of 1998, the Arc-er head was introduced as an upgrade for the previous LBH head. Although similar in design and use, the Arc-er head features an LED current monitoring system to assist you in maintaining optimal use of your Arc-er head and saves on electrode consumption.

You can also purchase the ultra-compact mini-mag 800 lb fixture or the portable magnetic base fixture which attaches to ferrous surfaces and provides 3000 lb holding power for use with your arc-er head. You can expect reliable heavy-duty service with your Arc-er Head which is designed to remove taps, drills, and studs up to 1″ diameter.

Electro Arc’s IQ Precision Disintegrator Head

IQ head on our test stand

The IQ precision disintegrator head is a high-performance head engineered for heavy-duty use. You can use this head horizontally or vertically. Thermal protection prevents any potential damage from overheating. You can use the IQ head to remove taps, bolts, drills, and fasteners up to 1″ in a single pass.

The IQ head is a standard feature for the following metal disintegrators:











The IQ head body enables smooth movement with 9″ of manual or automatic travel. This head is ideal for small taps from 0-80 or extremely large taps such as 2-inch taps or larger bolts such as 1 1/4-inch bolts and up. If you need to disintegrate carbide, look at the Servo head below:

Electro Arc’s Servo Disintegrator Head

Servo Head test burn

A high-performance disintegrating head, engineered for heavy-duty precision use. You can use this with electrodes from .020 inches to 1-inch diameter. You can use this machine to take out broken tooling including taps, bolts, drills, fasteners, etc. from 2# diameter in a single pass. Larger diameters are handled with multiple passes.

The Servo DC disintegrator head is standard on all of our DC machines.

We offer the full-size servo disintegrating head and a mini servo disintegrating head. The servo head is specially designed for heavy-duty use and comes standard with our most powerful machine, the Bolt Eater. This head disintegrates broken bolts 2 inches or larger. The mini servo DC disintegrator head is ideal for portable disintegration giving you ease of use at all angles and in small spaces.

Not sure what disintegrating head is best for your application? Try out our Machine Builder!

Why Do I Need DC Cutting?

D.C. cutting is direct current cutting, which is a naturally occurring process that moves metal from a positive pole (+) to a negative pole (-) when current flow is initiated (switched on) and subsequently interrupted (switched off). You may not know that this process is as old as the storage battery. It was also responsible for the problems of the early automobile ignition points and plugs – excessive wear on the positive terminals caused by the rapid switching of a D.C. circuit.

D.C. cutting is the basis for all convention and wire EDM machine technology (not to mention Electro Arc Metal disintegrators) and predates the electric light bulb.

DC Portable Metal Disintegrators Heavy-duty power for onsite or occasional use

How Does DC Cutting Work?

D.C. cutting or EDM cutting occurs when an ionized path is established (switched on) between a positive and negative pole and then broken (switched off) to stop the current flow. The simplest example is what occurs when the (+) and (-) poles of a car battery are momentarily (with jumper cables) touched together (switched on) and then pulled apart (switched off). When the cable clamps are examined you discover a crater on the positive clamp and an equal amount of material added to the (-) clamp – EDM in action!

Harness this D.C process to remove broken taps, drills, and bolts quickly and easily. Minimum heat is generated and low power is consumed because polarity is the major moving physical property. High amperage, can waste power as a violent arc is created generating excessive heat and causing extreme electrode wear.

How do Electrodes Work in the Metal Disintegration Process?

Did you know that any conductive material can be used as an electrode? The more conductive the electrode material, the more effectively an electrical process works, and this is an electrical process.

Electro Arc machines can be used with inexpensive copper tubing. Copper has superior conductivity (next to silver), low cost, and is easy to work with. It has the added benefit of being very conductive both electrically and thermally to aid in removing residual heat from the cutting area. We use other materials as electrodes for cutting operations where higher temperature arcs are required to remove high-temperature materials such as high-temperature bolts that are alloyed with molybdenum and other elements.

You need D.C. cutting because you are constantly searching for a better, faster, cheaper way to get your job done. D.C. cutting gives it to you because it moves metal faster through polarity while minimizing heat and power consumption through lower amperage requirements that always accompany the use of polarity as the major moving physical property.

How does D.C. cutting compare to A.C. cutting?

A.C cutting is the creation of a violent arc between a high melting temperature (molybdenum/melts at 4748 degrees Farinheight and 2620 degrees Celcius) electrode material and a lower melting point material (tool/steel/melts at 2500 degrees Farinheight and 1371 degrees Celsius) and the fact that the lower melting point material (steel) will melt faster than the high-temperature material (molybdenum). You will want to use DC current with carbide because it cuts faster than AC, you may also need a DC machine if you are planning to use your metal disintegrator on larger bolts.

Electro Arc’s AC metal disintegrators were the first metal disintegrators available on the market, released to the general public for purchase in 1947. While competitors came and went over the years, Electro Arc remained the best metal disintegrator manufacturer purchasing competing brands including Elox, AC machines are generally cheaper than DC machines and provide a larger variety of options for customization.

8 Recommendations for Electro Arc Machine and Operator Safety

Your Electro arc Machine is durably built, thoroughly tested, and inspected at the factory. You can expect many years of service with minimal maintenance. To maintain the accuracy, dependability, and cutting speed built into your metal disintegrator, please heed these warnings and recommendations for machine and operator safety.

Warnings: When connecting your machine to power – The Installer and Electrician must confirm that a solid ground exists between the cabinet and the building ground.


Recommendations for operator safety when operating your Electro Arc metal disintegrator:

  1. Use a splash bag or shop towel to control coolant splashing before starting the machine.

2. Avoid touching the operating head and workpiece/table at the same time while operating the machine.

3. Fasten your workpiece securely to avoid “walk” which can damage the threads in the hole.

Disintegration works on the principle of a vibrating spindle with an electric power supply creating a series of intermittent arcs. AC machines make and break 60 arcs per second and DC machines make and break 120 arcs per second to disintegrate the hardest metals. The particles created during the disintegration process are flushed away by coolant flowing through the center of the electrode.

4. Always refer to the electrode chart for Electrode sizing. Electrodes from .025 to .060 diameter draw very little amperage and will show little change on the current indicator.
Select an electrode that will only remove the center core of the tap. This will remove the core of the tap and leave the flutes standing in the threaded section. These may be blasted out with air or removed with a magnetic pick set. You will be left with a perfect threaded hole.

5. When you are removing broken drills, snap off the flutes after every two inches of cutting travel. This may be done quite easily using the same size drill and rotating it in the hole.

6. Removing Hardened Screws and Studs:
You need to select an electrode approximately .020 under the minor diameter of the thread. For a clean cut, collapse the wall of the screw – remove the particles and retap. This will clean out the male threads without damage to the female threaded section. You may also choose to disintegrate a square or hex in the stud and turn it out with the proper size tool.
Caution: Always make sure your electrode is straight

7. Replace the coolant frequently – Clean the tank every 4-6 hours of operation. The metal disintegration process creates abrasive particles which can shorten the pump life.

8. Please consult with Electro Arc if your machine is in need of repair.  If your machine is under warranty, do not attempt to make repairs prior to contacting our facility as it will void your warranty, additionally always consult with your operators manual for electrical diagrams, troubleshooting steps, and part numbers.

10 Ways you can use Electro Arc Metal Disintegrators

When you think of a metal disintegrator you probably think of removing broken bolts.  Electro Arc metal disintegrators have a variety of uses.  Disintegrating hard metal is easy with our machines!  A minute arc causes the disintegration process at predetermined intervals.  These arcs burn microscopic pieces of your work metal.

Here are just 10 ways you can use your Electro Arc metal disintegrator to save time and money by accomplishing in minutes what would have taken you hours or days to do in the past.

Broken Taps

You can use your Electro Arc metal disintegrator to remove broken taps from any material. A machine with an Arc*er head will remove taps between #6 – 1 1/4″.  If you need to remove between #0 and 2″ or bigger, the IQ head is built to disintegrate the largest and smallest taps.  If you will be disintegrating carbide, look into our DC metal disintegrators!

Broken Studs

You can remove broken studs  with an Electro Arc metal disintegrator.  Use one of our DC models to remove larger diameter studs (2.5″ – 6″) As illustrated below:

Broken Drills

Don’t waste hours removing broken drills.  Save money and salvage your parts.

Broken Reamers

When reamers break they can be especially hard to remove.  Use your metal disintegrator to remove broken reamers with no damage to your part.

Cut Round and Shaped Holes

Your metal disintegrator can be used to cut round holes without annealing the surrounding metal regardless of the rockwell hardness!

Cut shaped holes in hardened metals using shaped electrodes.

Preserve the thread when you remove large broken taps by disintegrating out the core.  Our magnetic pick set helps you remove the sections in no time!

You can remove small diameter drills from expensive parts saving you from salvaging expensive machine parts.

When you have a frozen stud our metal disintegrators can still save you time and money by removing the broken stud, screw or bolt with two cuts.

You may have wiped out half of the thread on your broken bolt trying to remove it, broken easy-out in the hole, made a mess trying to weld out a broken stud, or totally galled the thread when you were trying to remove that broken stud.  If you really want an easy solution for removing broken studs and screws, we have your solution!  An alternative to the “two cuts” method illustrated above?  The square hole.  When you disintegrate a square hole in your broken studs you can use an socket wrench to remove them!

Save your broken end mills!  As any machine shop knows, broken end mills can shut down operations costing your company more money per hour than you can afford!  Our Metal disintegrators will save your broken end mill and save you money immediately!

An Electro Arc metal disintegrator is an investment some companies use to provide metal disintegration services for time sensitive jobs!  Most of our customers need the metal disintegrator to continue operations this is especially true for power stations, petro-chemical works, oil equipment, offshore installation ships and general process industries.  In these industries every minute is worth thousands of dollars.  If you have key piece of equipment, that needs repair due to a broken fastener you need it now!  Easy out will not cut it in these settings!

Applications go well beyond just broken stud and bolt removal.  you can cut slots 1mm wide, and 10mm deep in heavy test pieces for calibration or deep cuts through seized clevis pins.  Orientation is never a problem with our versatile disintegrating heads!

Are you looking for more applications for your metal disintegrator?  Check out our new post 10 More Ways you Can use Electro Arc Metal Disintegrators.

What’s the difference between the LBH head and Arcer Disintegrating Head?

In November of 1966, Electro Arc announced the LBH head. A new fast-cutting disintegrator head for removing broken drills and taps. The model LBH disintegrating head incorporated a bearing-mounted, hardened shaft that increases cutting speed by providing extra rigidity. Simple construction reduced the amount of maintenance this head would need to the bare minimum. This head provided you with the option of disintegrating at any angle. You could disintegrate with electrodes from .010 up. At the time, this head was standard for Electro Arc metal disintegrators including the 3-S and 1-S.

The LBH head on portable disintegrator holding fixture

The LBH head is now obsolete. In September of 1998, Electro Arc released its replacement the Arc-er head. Now standard on a number of our portable and tabletop machines, the Arc-er head can also be used in a number of machine configurations. This upgraded head features a current monitor for ease of use. This feature allows you to easily determine when to adjust your disintegration.

The Arc-er head was introduced in 1998

Disintegrating head applications allow you to easily use the Arc-er head with a number of our metal disintegrators. Check out the configurations for your Arc-er head below. You can use the Arc-er Head with a number of machines in your shop. You can also use the Arc-er head directly on your workpiece. We also offer magnetic fixtures for use with your Arc-er disintegrating head.

What is Electro Arc’s Carbide Impregnator?

Electro Arc introduced the Carbide Impregnator in June of 1964. This bench-type carbide impregnator hardens wear surfaces of tools. You can use this process to extend tool life and reduce downtime and maintenance. Cratering, galling and chip abrasion are substantially reduced. You will find this plug-in-hand tool easy to use. A carbide tip is passed over the wear surfaces or land of the tool. The vibrating tip fuses tungsten carbide by electrical spark discharge into the metal surface. The carbide deposit adds hardness and wear resistance to the surface metal without altering toughness and other mechanical characteristics.

Examples from case studies show increased life of tools:

*Gear cutters – 700%
*End Mills – 800%
*Saws – 600%
*Piercing punches – 300%

How the Carbide Impregnator Works:

The carbide impregnator deposits tungsten carbide to a depth of .0005 to.001 in the metal and builds up to .0003 tolerance regardless of the length of operation. You can pass the impregnating tip over the surface many times until you are satisfied with the desired deposit. The impregnation process uses a special grade of carbide suitable for impregnation.

Electro Arc’s Carbide impregnator operates on a 120 volt, 60 cycle current. The cabinet is made with16 gauge reinforced steel with steel side handles for easier handling. A convenient expanded metal basket is used to store the plug-in hand tool and cord. The tool’s net weight is 35 pounds.

Applying the Principles of Carbide Impregnation

You are probably wondering what kind of applications the carbide impregnator has. We published an engineering bulletin in the 60s with a case study “Applying the Principles of Carbide Impregnation to Circular Saws” about Havey Aluminum Company’s application of the Carbide Impregnator. A prime extruder of titanium and aluminum in the United States, Harvy aluminum had a sizable investment in 36″ diameter circular saws for cutting billets. Numerous studies and reports for cutting manufacturing costs and determining shop procedures revealed that no saws of any kind would stay “on the lin” for more than 12 hours, and it was best to stop to change at six and three-quarter hours because of a variety of negative factors which thereafter started to develop.

Harvey Aluminum gave Electro Arc a 16″ circular saw with 80 teeth to carbide impregnate, the theoretically critical crescent of about 1/64 of a square inch on each side of the teeth. The carbide impregnation of the 16″ saw took about two hours. Harvey Aluminum then put the saw into operation and inspected it at the end of 80 hours of continuous operation. They found there was an increase of over 600 percent over any other saw used before.

On the strength of these results, Harvey Aluminum immediately purchased an Electro Arc Carbide Impregnator so that they could continue to receive this extraordinary increase in all of their saw operation. In addition to this, after receiving the machine they began to experiment in other areas of their plant operations. The Extrusion Department impregnated four sets of dies and reported an increase of over 1000 percent. Further use proved that the slitting saw operation was further improved by impregnating the entire tooth rather than just the crescent.

This application at Harvey Aluminum is an excellent sample of what users of the Electro Arc Carbide Impregnator experience when they have the chance to couple the impregnator with their own knowledge against wear-life problems.

What Material is Most Efficient in the Disintegration Process?

First of all, what is an Electrode?

An electrode is an electrical conductor, Electro Arc electrodes, formerly referred to as Disintrodes, are hollow tubing made of graphite, copper, or Molybdenum.

Electro Arc machines will operate with any material that conducts electricity as the electrode. Metal disintegration works on the principle of vibration, electrical spark, and coolant. The cutting power is a low voltage rectified DC current. Sixty sparks are discharged a second between the electrode and the workpiece. The coolant is passed through the hollow electrode onto the workpiece causing a thermal shock (heat and coolant). The material is fractured into minute particles and washed away by coolant. Both the electrode and the workpiece erode during the cutting process. With this in mind, the following information should then be considered.

Melting Temperature of various materials:
Molybdenum 4600 degrees F
Copper 2000 degrees F
Brass 2000 degrees F
Steel 2500 degrees F

Attaching an electrode

It is important to use an electrode material that will break down less than the workpiece. Molybdenum has this advantage. The melting temperature is double that of the other electrode materials, which means you will erode more of the broken tool and less of the electrode. The disintegrating time will be faster and the labor cost lower. In comparison, other lower melting materials, such as copper, erode as rapidly as the work material raising the labor cost for removing broken tools. Molybdenum is a more expensive material to use as the electrode; however, the savings in labor in removing broken tools more than justifies the cost – a proven fact in the industry for over 25 years. Thousands of disintegrator customers use molybdenum or comparable high-priced material in the electrical discharge process.

Electro Arc electrodes are recommended for removing broken taps, drills or disintegrating any other hardened materials. A 12″ long electrode will remove approximately 30-35 taps. Studs and bolts, because they are not as hard as taps and drills, will cause the electrode to erode somewhat faster.

Electrode chart for removing various size screws:

1/4″ diameter screw requires a .200 diameter electrode
5/16″ diameter screw requires a .250 diameter electrode
3/8″ diameter screw requires a .290 diameter electrode
1/2″ diameter screw requires a .375 diameter electrode
9/16″ diameter screw requires a .437 diameter electrode
5/8″ diameter screw requires a .500 diameter electrode
3/4″ diameter screw requires a .625 diameter electrode
7/8″ diameter and larger screw should be removed by making two or three holes in the screw or bolt.
The diameter of these electrodes are close to the tap drill size for various threaded holes. After disintegrating you should be able to run a tap into the hole to remove the remaining shell. When making two or more passes to remove a stud, a certain amount of picking time is required to remove the remaining pieces.
Please see sizing an electrode for information about which electrode to use for an AC machine, which electrode to use for a DC machine, which electrode to use for a bolt eater, and methods to remove bolts, dowel pins, and drills with graphite electrodes or molybdenum electrodes. Contact us to purchase electrodes.

Black VS clear Splash bags for your metal disintegrator

What is a splash bag?

Electro Arc metal disintegrators use a thick clear or black “splash bag” to contain the coolant which is continually running through your Electro Arc metal disintegrator and the sparks metal disintegration process creates.  This plastic bag is custom made to fit the area between the head of your metal disintegrator and the item you are disintegrating.  Splash bags contain the coolant and shield the operator from sparks during the metal disintegration process.  A splash bag is attached to the metal disintegrator head to cover the area you are disintegrating.

Electro Arc metal disintegrator set up with a black splash bag

The advantage to using a clear splash bag is that you can see the metal disintegration process, but this also means looking into the arc weld sparks produced during metal disintegration.  However, as you are operating your Electro Arc metal disintegrator, your attention will be on the power controls and auto-feed functions so it is unlikely you will be looking directly at the metal harmful arc welding sparks anyway.  The sound of your metal disintegrator will clearly indicate to you the progress that you are making with the disintegration job you are conducting and the process is quick, so there is no reason to be staring into potential eye harming arc sparks. Please note that we do not have clear splash bags available for purchase.

As weldors know, eye protection is required during the welding process because the infrared light can cause permanent damage to your eyes and lead to cataracts. The advantage to Electro Arc metal disintegrators is they do not require welding experience to operate.  Anyone can learn to set up and use an Electro Arc metal disintegrator. Black splash bags provide protection for your eyes and eliminate the potential hazard to your eyes.  We prefer the black splash bags here at Stillion Industries.

How many splash bags do I need?

If you are conducting regular metal disintegrating jobs with your Electro Arc metal disintegrator, you will likely use a lot of splash bags.  You will need to use a splash bag each time you use the disintegrator.  The good news is we sell them in packs of 50! 

Do I have to use splash bags?

We highly recommend that you use splash bags to ensure the safety of the operator of your Electro Arc metal disintegrator.

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 machiningspark erodingdie sinkingwire 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.
Electro Arc