I run my own small workshop as well as a garage wherein I come across different metal cutting tasks. At times, I need to cut through really thick steel sheets, say of almost an inch in thickness.Similarly, I also have to cut to through really long sheets of copper. When I started this home business three years back, I knew that a plasma cutter is perhaps the most efficient tool for me to handle such diverse tasks.
This is perhaps because in the welding world, such a tool offers an optimal blend of speed, prudent fuel use, finest outcome, safety, ease of use, and least flaws, when used with the right welder. Since 1960’s, plasma cutters are popular for their quickest and finest cuts without much hassle or errors.
Further, they are also admired for their versatility, as they are capable of cutting copper, aluminum, steel, and stainless steel to mold into any size and shape. However, the unit in use should be robust enough to handle the thick and long metal with a longer duty cycle.
However, I was hesitating to go for a plasma cutter. Why? This was because these tools were really very expensive, which I thought only industrial owners could afford. This was a fact that I could not ignore at that time.
For me, investing this much money was impossible due to strict budget.Apart from the cost, even safety was an issue, as there are some risks associated with a plasma cutter. Still, I managed to get the best plasma cutter for myself that is not risk to operate. How did I get it? Well, read on…
I followed the below steps for the same:
- Research on cost
- Buying factors
- Top 5
- Read Plasma cutter reviews online
- 1 Step 1: Research… Findings Were Very Surprising!
- 1.1 Overview of Plasma Cutters: What Are They
- 1.2 What Can One Do/Get Using a Plasma Cutter?
- 1.3 How Do Plasma Cutters Work?
- 1.4 What Are the Benefits of Plasma Cutting?
- 1.5 What are the Different Types of Plasma Cutters/Plasma Cutting?
- 1.6 What to Consider before Buying the Best Plasma Cutter for You
- 2 Step 2: Buying Factors to Consider
- 2.1 Input and Output Power (Voltage and Amperage)
- 2.2 Cutting Capacity
- 2.3 Inverter Technology
- 2.4 Portability
- 2.5 Duty Cycle
- 2.6 Torch and Arc
- 2.7 Start Type: Pilot Arc vs. High Frequency Models
- 2.8 CNC Cutter Type
- 2.9 Cooling
- 2.10 Consumables
- 2.11 Air Supply
- 2.12 Desiccant Air Dryer & Filtration Systems
- 2.13 Environment
- 2.14 Control Panel: Indicators and Controls
- 2.15 Housing
- 2.16 Accessories
- 2.17 Brands
- 3 Step 3: 5 Best Plasma Cutters of 2017
- 4 Conclusion
Step 1: Research… Findings Were Very Surprising!
So, I went ahead and did some research about how costly a plasma cutter can be and whether or not there is a chance of getting an economic model.
Well, the research gave me quite surprising findings.
As usual, technology becomes more affordable with the passage of time although initially it is costly. This is exactly what has happened with these metal cutters. Initially, they were extremely costly due to which they were hardly attainable for a home or hobby user.
However now, they are astonishingly more affordable than before. This was a great sigh of relief for me, as I was now convinced to have a quality unit at a relatively low price and without compromising the latest features. Wow!
Coming to the risks, they are now reduced if you choose the best model. Though the risk of accident is always there, it is globally admitted that these tools are safer than oxy-fuel cutters, especially those that utilize acetylene.
Conclusion: Plasma cutters are no longer costly or that riskier. Even a hobby or home user can buy it and ensure one’s own safety.
With this conclusion, I started digging more about plasma cutters as someone who knows nothing about plasma cutters. Well, I was so happy to dig that deep, as I was able to understand plasma cutters comprehensively.
To be frank, this comprehension was necessary to buy the best plasma cutter for my tasks. I am sharing the understanding here in the form of sub-topics below, so that even you know in advance what you will be buying for cutting through different metals.
Overview of Plasma Cutters: What Are They
Aim: To know what a plasma cutter is
Plasma cutter is a tool that acts as a metal cutter. It is designed to melt a metal for cutting it. It does so by utilizing an inert gas, which is emitted from the tool’s nozzle at a high speed.
Simultaneously, an electrical arc is applied to the released gas to turn it into plasma – the highly heated ionized gas and the fourth state of matter. This results in a very hot torch that cuts easily.
A few metals are tough to cut due to which they require a gas that works as a catalyst so that the concentrated gas converts into plasma. These tools are expert in rendering precise and even cuts that are finer than the suitable torches of the past.
For a variety of industrial uses involving metallic cuts, a plasma cutter is indispensable. It is essential right from cutting steel to molding dissimilar structures, from sizing a thin or thick metal into a big one, and from piercing a thick to thin steel sheets.
In the world of creative metal art, a plasma cutter is used to obtain different shapes and designs. In the industrial world, it is used to cut rough sheets, which are then used for different purposes at auto repair shops, building sites, and rescue yards.
Today, these tools have become the de-facto metal cutting method in home as well as professional work environments. This is perhaps because of the reduced prices and unmatchable cut quality as well as ease of operation.
A plasma cutter is a valuable asset for home metal workers and professional welders.
Plasma Cutters versus Other Tool Cutters
Precisely, plasma cutting is a process through which metallic sheets are cut to form different sizes and shapes. Yes, you can do the same process with a cutting scissor or another similar tool.
However, these tools will not be feasible if the quantity is large or humungous. These tools will also consume more time than expected.
Even the biggest scissor will be unable to cut sheets thicker than those of your waist. This is exactly where a plasma cutter is the most reliable tool.
With a big scissor if you managed to cut, the edges will not be smoother. The expectation of smooth edges is one of the primary reasons behind people choosing a plasma cutter.
Through a really fine technological process, plasma cutting cuts a highly thick sheet of metal so finely that there are no jagged edges. A steel scissor may damage the edges, while manual or freehand cutting lacks uniformity across the working space. These tasks need a lot of energy.
A fine and sharp plasma cutter is required for cutting through big sheets in the queue.Right from big industrial factories to small workshops, a plasma cutter is handy to cut especially thick materials and metals easily, accurately, and efficiently without much labor.
Personally, I feel that a plasma cutter is both time and life saver while performing many risky jobs. I have to perform several tasks quite frequently, which were quite tedious with hand tools. With this tool, these irksome tasks have become pleasant and effortless.
I am always surprised to know how much time is saved after finishing each cutting task. That’s the beauty of these smart cutters! The newer models have replaced the transformer with an inverter to ensure cooler operation, lighter and smaller design, and ease of handling.
Today, plasma cutters are available in a variety of shapes and sizes, right from economical and portable units for home use to massive Computer Numerical Control (CNC) models for industrial use.
Obviously, I focused more on the portable variety suitable for most DIYers, hobbyists, and light cutting business requirements.
Plasma Cutting versus Oxy-fuel Cutting
Aim: To know the difference between plasma and oxy-fuel cutting, as both are quite useful
Plasma cutting is preferable for any conductive metal such as stainless steel and aluminum. In case of mild steel, the performance is faster than with alloys.
Oxy-fuel operates by oxidizing or burning the metal due to which it is restricted to ferrous metals such as steel, which are fine with the oxidizing process. Other metals such as stainless steel and aluminum results in an oxide that hinders further oxidization due to which oxy-fuel cutting is not possible on them.
On the other hand, plasma cutting need no oxidation. Therefore, it is capable of cutting any conductive material. Further, it does not need fuel gas or compressed oxygen. It only needs compressed air, which is readily available.
It is easier for a beginner to master plasma cutting. On thinner materials, the process is quicker than oxy-fuel cutting. Nevertheless, oxy-fuel is ideal for heavy steel measuring 1 or more inches in thickness, as it is quicker. In case you use plasma, you need a really high capacity power supply.
Oxy-fuel cutting mandates manual control of the cutting speed for sustaining oxidization. However, the process of plasma cutting is more liberal here. It is ideal for a few niche applications, such as cutting through an expanded sheet, which oxy-fuel cutting cannot do. Plasma can also make non-linear cuts easily.
What Can One Do/Get Using a Plasma Cutter?
Aim: To know the applications/uses of a plasma cutter
A plasma cutter is a versatile tool for working with metals measuring less than 1 inches in thickness, which are used for building or repairing jobs. The number of tasks you handle with it is really significant enough to save much time for other jobs. Here are a few tasks/projects for which a plasma cutter is just essential
- Cutting a metal to obtain a desired length
- Cutting steel to create a welding bench
- Cutting metal for repairing the broken frames of a trailer
- Cutting a tube
- Making trailers
- Making metal sculptures or custom tool boxes
- Making fences
- Making a fuel tank
Well, this is just a few examples. The list is actually longer than the above on. Just have this tool and you will be able to do almost anything with a metal. This is why I call my plasma cutter as the “Universal Performer!”
How Do Plasma Cutters Work?
Aim: To know how the tool cuts through a metal
A plasma cutter consists of a nozzle via which the gas/air is passed, a handle for direction, and an electrode. The tool sends an electric arc via a stream of high-speed inert gas that passes out from a nozzle or a narrow opening.
The gas can be compressed air, oxygen, nitrogen, and so on. The temperature of the gas rises such that it enters into the plasma state, during the process.
The hot state of the plasma enables you to cut a metal. Further, the electrical activity of the plasma enables the arc to transmit the work while cutting.
The nozzle allows the gas to move at a high speed for making the cut possible. The gas inhabits the perimeter of the cutting region, allowing the tool to protect or shield the cut.
In the best models, a pilot arc between the electrode and nozzle is incorporated for gas ionization and plasma initiation prior to the arc transfer.
Unlike other cutters such as saws which leave behind bits and fragments, a best plasma cuts quite cleanly to leave just a handful of debris. You can easily remove whatever is left.
Further, you can expect a great detail, as you can cut via fine lines along a thin surface without using too much heat. In several classic handheld models, the consumable parts of the electrode and nozzle tend to touch each other within the torch if the unit is off.
Once it is turned on, the power supply forms a Direct Current (DC) that passes via the connection within the torch. When this current flow starts, it initiates the flow of gas (usually compressed air).
This air generates pressure, which is sufficient to separate the nozzle and the electrode. At the same time, the electrode covers the nozzle to increase the temperature of the gushing gas. As a result, an electric spark forms, which transforms the air into a plasma spout.
This plasma contacts the metal to weaken it for easy cutting. The DC current then moves to nozzle from the electrode and finally reaches the metal piece. Both the gas stream and current last until you release the trigger.
By using the air and an electric arc, a plasma cutter tends to utilize both wire speed and high pressure with a low heat for giving the smoothest cut.
What Are the Benefits of Plasma Cutting?
Aim: To know how advantageous the tool is for my tasks
- Faster cutting than manual processes, regardless of kind and size of metal (10 times faster than a saw)
- Efficient on all conducive metals regardless of the thickness
- Automation due to electrical control
- Smooth and precision cutting
- Boosted productivity
- Free labor for other tasks
- Low noise level and no vibration on the work piece
- Fine, robust, and precise arc for no slag
- Least residue
- Use under water in a few circumstances
What are the Different Types of Plasma Cutters/Plasma Cutting?
Aim: To compare and contrast the available methods or types
Many conductive materials such as steel, tin, and aluminum require a precise, refined cut for an apt welding so that they become useful for a variety of industrial purposes. For a precise, fine cut; you need the right plasma cutter along with the right plasma cutting technique.
However, not all types of steels or other metals are compatible with a single model of plasma cutter. Thus, different grades exist to specify the desired cutting level as well as the environment.
As a result, plasma cutters are made with varying ratings of voltage and current. With different combinations, various ratings are available for obtaining the precise metal cuts.
This brings us to two distinctive types of plasma cutting namely, High frequency and Blow back. Each of these processes involves a unique mix of a particular voltage and current setting. So, looking for these ratings and ensuring that they are what you need is the first step for getting the right model.
- High Frequency: Is for heavy-duty tasks and is quite rigid.Plasma cutters implementing this method have a sensitive torch like nozzleto pierce thick sheets at a high temperature. The electrode applies the arc to the work piece for precise cutting. With such a method, do not expect any loose end on a finished surface.
- Blow Back: Is the simplest form and handy for flawless cuts at a low cost as well as on a big scale. It is preferable over high frequency method when you need to cut steel sheets randomly. This is because the high frequency method process to be expensive in this case. The blow back process is commonly used for tin cuttings, board piercing, and manufacturing home appliances. In this process, a gas mixture is released via the nozzle as soon as the metal piece comes in direct contact with it. This makes the nozzle to puff long flames instantly, which scorches the surface and cuts off the sheets at a high temperature. For this process, you really need a lightweight model.
Pros and Cons of Plasma Cutting Methods
Pros of High Frequency Plasma Cutting
- Easy cutting of thick to thicker steel sheets as per the expectations
- Smoother, exactly precise, and refined outcome
- No loose end while cutting surfaces of different thicknesses and grades, unlike manual and other plasma cutting processes
- Suitable for propeller sizing and cutting engine grooves
Cons of High Frequency Plasma Cutting
- Costly due to consumption of much power (expect hike in power bills)
- A bit more time consuming than other cutting method
- Mandatory safety measures that are also costly, as inert gasses are mixed with flammable stuff
- Risk of cutting your working base if uncontrolled
- Risk of electrical interference with other devices such as computer, as it uses a high voltage spark
Pros of Blowback Plasma Cutting
- Lighter in weight than the high frequency models although it is still not easy to carry and transport them
- Easier to learn and cut mid thick to thin sheets
Cons of BlowBack Plasma Cutting
- Lighter in function
- Inconvenient for cutting sheets over 38mm in thickness
Other Categories of Plasma Cutters
You will even find manual and automatic plasma cutters.
- Manual: Needs guidance from the user. Such a model is economical, lightweight, portable, and needs no specialized training or installation by multiple personnel or of a special circuit. The steadiness of the hand determines the level of cut’s smoothness. However, you cannot operate such a cutter for a long period.
- Automatic: Comes with already set cutting tables as well as a circuit system forguiding the motor. Such a model is designed for industrial tasks, as they can cut thick metals quickly as well as uniformly. Nevertheless, these models are expensive and need more space as well as special training.
What to Consider before Buying the Best Plasma Cutter for You
Aim: To know the prerequisites or the necessary details for buying the best plasma cutter
Considering that there are many models to buy, it can be a confusing task to find the most suitable model. Thus here, you need to go logically.
First, you need to know your needs/requirements along with the budget. This is possible to find out quickly by answering the following questions, before you move ahead:
- What kind of metal or material you intend to cut and what will be its thickness? This will help in choosing the model that is designed specifically for your material/metal.
- What will be the duration in a day for which you plan to use the tool? This will help you in choosing an efficient duty cycle.
- What is your budget? This will help you in choosing a model that fits in your budget.
- Where you will be working with the plasma cutter?
- Will there be an electrical socket? If yes, then is it 30 amps, 110v phase or 50 amps, 220v phase?
- Will there be other tools using the same socket? If yes, which are these tools? Knowing these details help you choose the model with the right power specifications.
- Is portability important for you?
- Will you be taking it at the job site or use it in your shop or garage for most of the times?
- Is there a way to provide compressed air at a remote site? If yes, what is it: Bottle or a portable compressor?
- How will you provide current at the site?
- Will you use a CNC cutting device with the plasma cutter or totally go for manual cutting? This will help you decide whether you need a model with CNC or not.
While you answer the aforementioned questions, it is sensible to keep some things in mind. They act as guidelines for choosing the best or most apt plasma cutter as per your requirements.
- The higher a model’s amperage output, the more is the duty cycle atlower amperages. This means you need a bigger unit than you require in case you wish to use it around the clock.
- It is important to know the cut rating of plasma cutters, which indicates the thickness that it cuts cleanly while stirring the tip at around 10 Inches Per Minute (IPM). This rating is directly related to the amperage output.
- Consider a model capable of passing through the thickest surface in case you will use it frequently, and not continuously.
- Choose a model that cuts the thickness efficiently, which you will be dealing with often. There is no point in going for a heavy-duty unit if you will not be dealing with a3/4-inch thick metal.
- Consider a model that can cut twice the thickness you will handle, if you will start by piercing the metal, and not by handling from an outside edge. It is vital for the tool to pierce the metal quickly or else the molten part might splatter back on the torch’s tip to reduce its lifespan.
- Never ever think that a greater capacity model is always better.
- Avoid a plasma cutter for cutting a 1.5-inch plate in case you are using acetylene for the same.
- Consider a 220v and 50-80 amps’ model for non-ferrous metals, which oxy-fuel cannot handle.
- Go for a new semi-potable unit if you will be using it occasionally outside the shop occasionally. These models are below 100 lbs. and yet cut 0.75-1 inches of thickness quickly.
- Avoid selecting a high frequency unit if you have a plan to automate plasma cutting even later.
- Keep in mind that you get what you invest in. So, it is okay to invest in a bit costlier inverter kind model, as you will later not have to spend in its repair and replacements.
Step 2: Buying Factors to Consider
With new technologies emerging in the field of welding and cutting, plasma cutters are getting available with improved designs and technologies. However, there is no single model fit for all.
Different users require varying functions, depending on the type of use that can be commercial or non-commercial. Simultaneously, different types of metals are handled for cutting. You need to consider all these factors while buying plasma cutters.
In short, plasma cutters differ in terms of performance, cutting method, utilities, durability, and maintenance. Once you know your needs and budget, you can shortlist the most promising models.
However, to choose the most suitable model without allowing the variety to daunt you, just consider the below buying factors and the rest will be quick, easy, and smooth. With these factors, it becomes easy to compare and contrast.
Input and Output Power (Voltage and Amperage)
A few while ago when you were reading this post, I had specified that checking out the voltage and current ratings or specifications is the first step toward the most suitable plasma cutter. So, this is the first factor to check out for.
Power specifications or ratings directly affect the pricing of a plasma cutter. This is because they determine the thickness of a metal piece it can cut as well as the speed at which it can do so. Power specifications are based on voltage and amperage.
Units that run with a standard 110/120v electrical outlet are more economical but are confined in terms of work level they can handle. On the other hand, models that come with dual-voltage capabilities tend to work with 220/240v heavy-duty outlets, and cut thicker surfaces. However, they are costlier.
You also need to check the wire configuration if you need to screw it into the tool’s body. In some models, this is only done for your convenience.
You can wire most models at 110, 120, or 220 volts. An outlet of 220v is something that your home will not have, which you need to keep in mind.
In case you have such an outlet, it is sensible to choose a model handling high voltages.Usually, plasma cutters run at three different voltages namely, 115, 230, and 115-230v (switching), which depending on the plug.
Majority of models come with a blend of 110 volts and 30 amps, or 220 volts and 50 amps. Many of them provide a dual meter so that you can adjust the amps as per the requirements.
What is important for you to understand is that high input power is required for working efficiently. Further, if the outlet’s same circuit will be used by other appliances, it is wise to have a dedicated or a separate circuit for your tool. Otherwise, the input power will be less.
While selecting a plasma cutter, go for the one that has the critically vital feature called the Line Voltage Compensation. Through it, the tool manages voltage fluctuation.
Further, it becomes capable of adapting to alterations in the power supply while retaining the speed and a steady arc and preventing the circuit board from blowing off.
This is the output power or electrical current for generating the arc and is measured in amps. Amperage directly affects the ability to handle various metals and thicknesses, magnitude as well as duration of usage in a single session, and speed and cleanliness of cuts.
So, knowing about the amperage is essential to have the right cutter.Because plasma cutters are available in different amp ratings, it is essential to match the amps with the metal’s thicknesses as well as with the existing power source.
Generally, plasma cutters produce 30-50 amps, which is more than sufficient for most cutting jobs. A few models come with a higher rating of around 200 amps. These units often act as welders and are designed for more heavy-duty tasks. Obviously, these models are the most expensive ones.
In short, a higher rating means greater output power as well as an equally higher cost. So, if you know that you will cut only thin metals for home or small hobby projects, a model with 30-40 amps is just fine.
As a tip, go for a unit whose minimum amperage rating is well met by the outlet.
You need to keep in mind that power output is directly proportional to that of the input. A few models can operate with the standard 120v 15A home outlets but others need 20A at least. The more powerful units of 220v need 50A.
Thus, do check the power outlet at the site where you will work with the cutter. This will also determine whether you need an electrician to install the required outlets.
So, how do you decide which power ratings are the best or suitable ones? Well, this brings us to the next critical factor.
This shopping factor covers two aspects: Cutting thickness of the material and cutting speed. It is also one of the most significant factors that help you compare the shortlisted plasma cutters. Based on the cutting capacity, the price tends to differ from one model to another.
This refers to the maximum thickness of material that you can comfortably cut without compromising smooth edges. It is one of the most important specifications to check. You need to know the metal type as well as its thickness to know how powerful your plasma cutter needs to be.
It is best to start with the materials that you need to cut quite often. Acting wisely, you need a model that can cut thicker materials than the standard thickness you deal with.
This gives an impression of purchasing more capacity than needed but it acts as a versatile unit when it comes to cutting thicker material for obtaining high precision cuts. Such a unit usually comes with extra features.
Thus, the more the thickness a model is capable of piercing through, the greater is its price. So, it is rational to know what you need to cut, prior to looking for a plasma cutter.
Below are some guidelines for choosing the model as per the material/metal thickness:
- 1/4-inch Thick or Less: 25 amps (economical and low-amperage cutter)
- 1/2-inch Thick: 40-50 amps
- Over 3/4 and up to 1-inch Thick:Above 80amps
As the name suggests, the cutting speed indicates how fast a model can cut through the varying thickness levels. It is worth remembering that higher the amperage, the more is the cutting speed.
According to one of the top brands Miller Electric, there are three cutting rates, which are as follows
- Rated Cut: Refers to the cut thickness of mild steelhaving less thickness with a minimum cutting rate. With this cut, you get the best quality due to low speed of 10 IPM. You can expect a high quality cut from this speed.Because the metal is not that thick, the resulting output is smooth and clean.
- Quality Cut: Refers to the cut thickness of a thicker metal that can be cut but at a slower speed than 10 IPM. Consider this type of cut for having good quality of output from a thicker material although it takes a bit longer time.
- Sever/Severance Cut: Refers to the maximum cut thickness a model can tackle but with a very lower speed. However, you achieve the maximum output. The resulting cut might need some clean up. The term is seen as a specification for ESAB cutters. Consider this cut for highly thick materials but do not expect a very clean output. Initially, the speed is slow but it increases, as the thickness of the material decreases.
Different units provide different cut quality. The ones that provide a more precise and finer cut tend to cost more. However, the cost is not that high. A few models will offer all three cutting rates. However, such models are usually costly.
Inference for You: You need to know the material’s thickness and the desired speed for getting the desired cut quality.
You can easily find about the cutting capacity factor while reading the best plasma cutter reviews. Most models perform a 1/2-inch clean cut with a fast hand and 1 or 5/8-inch sever cut with a stable hand and patient mind.
When it comes to handling a thickness of below 2 inches, a plasma cutter is a better option than a cutter using the oxyfuel. This is because it gives cleaner as well as faster cuts.
Note: A few models might specify the maximum severance thickness. This is not the same as maximum cut thickness. The former is the absolute thickness a metal can have for a plasma cutter to handle it. Mostly, sever cut increases the probability of additional slag or jagged edges, which is not for those who need optimal and clean output.
Larger models tend to consume more power but cut faster, while others usually consume less power but have a slower cutting speed. Your cutting frequency determines whether you need a small or large unit.
This technology is in the form of a built-in inverter, which all plasma cutters do not have. The ones that come with an inverter are costlier than the ones that do not, but this extra money is offset by the included portability as well as boosted functionality.
So, if portability is on priority for you, the best plasma cutters are the ones that have a built-in inverter. Such models enable users to work comfortably at remote sites with no power outlet.
They need DC current for feeding the power via a transistor inverter. Such an inverter is of high frequency, ranging approximately from 10 to 200 kilohertz (kHz). As a result, the unit is quite smaller as well as easier to carry.
This is how the inverter technology makes an appeal to all mobile users of plasma cutters. The digital inverter technology not only saves space by being compact but also facilitates efficient and quick cuts due to its high cutting frequency.
Inference for You: Go for the inverter technology even if the price seems to be costly, in case you are a mobile service provider.
This is an utmost essential factor to consider if you will be moving with a plasma cutter from one site to another. A portable model comes with some handy, additional features for ease of transportation such as an ergonomic or comfortable handle and built-in storage for storing consumables.
Talking about the weight, it is usually not more than 60 lbs. A unit measuring 100 lbs. might not make affect when it is on your shop cart but the difference is felt while moving it around. The lightest models usually have a weight of 21-30 lbs. They are perfect for portable cutting at different sites.
This term refers to the duration within every interval of 10 minutes, during which the unit cuts safely without getting overheated. It is expressed in the form of a percentage and is computed by the amount of amperage the cutter pulls. Duty cycle tells you for much time you can use the plasma cutter.
In other words, it is the percentage of cutting time to cooling time. For instance, if the duty cycle is 50% at 50 amps, it means that within a period of 10 minutes, 5 minutes are for continuous cutting and the remaining 5 minutes are required by the machine to cool down.
In other words, at 50 amps that is required for a 1/2-inch cut, the unit runs for 30 minutes every hour without getting overheated. It makes cuts requiring 50 amps for 30 minutes. Similarly, if the duty cycle is 100% at 30 amps, it means the unit needs no cooling time and it works incessantly for full 10 minutes.
It is important to know that the duty cycle is directly proportional to the amperage output. The more the amperage output, the longer is the duty cycle as well as the price.
A longer duty cycle is required for those who work for a longer spell. For working for a shorter spell, duty cycle is a less important factor. A shop user may need a duty cycle of 50% or more, while a home user is fine with 35% duty cycle at the amperage output.
If you will be using a plasma cutter quite frequently but not incessantly for a long period, you only need to consider the maximum amperage output. However, if you need to use it continuously for longer shifts, you also need to consider the average or maximum material thickness with which the cutter is compatible.
Torch and Arc
Torch refers to the compressed air or gas moving at a high speed through the nozzle. In the center, a negatively charged electrode generates an electric arc. Due to the high velocity, the gas transforms into a flame called plasma.
Along with quality that differs from one plasma cutter to another, the cutting torch is also of great significance. This is perhaps because the torch is responsible for the overall quality of the cut as well as for the performance of the unit.
The best plasma models come with a new torch. However, in some models, there are customized torches whose trigger is movable as per your preference.
The torch’s head might be also of a low profile so that it reaches even the tight spaces. In most models, you can use the trigger in thumb as well as finger positions.
It is best to have a torch with contact arc. This is because it overcomes the possible incompatibility interferences as well as complications due to arc initiation. Such torches tend to possess capacitative startup mechanisms repellant to computer machines, and high voltages.
You need to select a torch that aims to provide consistent as well as quality straight cuts. For this, do check the bevel, which is related to the cutting edge and its straightness.
If you want fine cuts, you also need to check the kerf width. This is the measure of such cuts. For this purpose, you need a torch that fits into a small cavity.
Start Type: Pilot Arc vs. High Frequency Models
Generally, plasma cutters come with two types of startups namely, high frequency and contact/pilot arc for triggering the arc.
Most models come with a pilot arc that prohibits direct contact between the torch and the material to be cut. Such a type contributes to increased life of the nozzle. A few devices also have starter sets, which enable positioning the torch and accurately observe the arc.
While both high frequency and pilot arc models are reliable, the latter ensures an easier arc strike as well as longer lifespan of the consumables. On the other hand, high frequency models are more affordable and generate a more stable arc.
However, they require to begin from scratch as well as in close proximity with the metal. This actually alleviates the lifespan of the consumables.
Another comparative point to know is that the models with high frequency is likely to interfere with other electrical devices such as computers. However, pilot arc models do not create any such interference.
Still, several modern appliances are protected from such an interference, which might push you to go for a high frequency cutter, if it was the only issue. If you will be using a plasma cutter while performing an automated process, a model without a high-frequency startup is feasible.
Otherwise, a much higher voltage results in electrical interference that can ruin your computers. Here, you need pilot arc cutter, which has lower voltage.
You can choose any one of the two, as per your need.
CNC Cutter Type
Of all the different models of plasma cutters (differing as per the start type), a CNC plasma cutter is perhaps the most expensive as well as a massive one. So, it is worth determining as to whether you need such a cutter or not.
A CNC model cuts thick metal sheets quite finely without distorting the surface. However, unlike other plasma cutters, a CNC model uses a computer that is embedded into it.
The computer-regulated robotic arm controls the metal sheets while cutting and escort the torch over the work surface for making complex patterns.
Because of the computerized control, the output is more precise. This persuades the manufacturing and fabricating shops to choose a CNC model. Further, with such a model, it is possible to put heavy-duty materials in the cutting queue to save additional manpower.
However, these models need more attention than other types,during the initial period. You need to ensure that each section is ready to get started. Further, you need a glass door between the tool and yourself, as the plasma arc emits UV rays back and forth, which is risky for health.
Still, with a high precision, a CNC plasma unit is preferable for commercial tasks such as making a metal art and an intricate duct work.
The best plasma cutters also come with some feature or utility to ensure cool air flow so that the machine does not heat up much. Usually, it is in the cutter’s middle area where heat normally gets trapped.
Thus, it is essential to have an effective cooling mechanism that shall extend the duty cycle. Such a system also keeps dust or dirt away so that the components do not become vulnerable to damage due to its accumulation.
Consumables refer to the components of a plasma cutter that are bound to wear out because of usage. Of all, the nozzle and electrode tend to wear the most as well as quickly.
Inside the torch, the temperature of the arc is around 25,000 degrees Fahrenheit. Because it is made up of copper, nozzle has effective heat transfer ability. Nevertheless, at 1,100 degrees Fahrenheit, copper tends to melt.
Thus, compressed air flows within the nozzle such that it forms a hurdle between the copper and plasma heat to keep it away from melting.
Similarly, made up of hafnium that is excellent at releasing electrons, electrode is also exposed to this plasma heat inside the torch. As a result, hafnium tends to evaporate slowly and consequently the torch starts to backfire. Finally, the cuts tend to become less accurate.
So, it is essential to change these consumables on a regular basis. While the handheld torches are adjustable to control these effects to some extent, the CNC consumables need a relatively quicker replacement for ensuring continued accuracy.
It is sensible to consider consumables while choosing the right plasma cutter. If one model is more economical than the other but needs costlier consumables or more regular replaceable consumables, you are likely to end up spending lavishly in the long run.
While buying the cutter, do go through the specifications, as they include the estimated lifetime of the consumables. Depending on the usage of the model, a costlier plasma cutter with a longer lifespan of its consumables makes you save significantly in the long run.
The cost and life of consumables is rated as per the time the torch takes to cut metals prior to replacing the consumables. They are also dependent on the price of the torch.
You will need an inert gas for operating a plasma cutter. Usually, compressed air is used, although some users consider adding dry air to it for discarding moisture for better performance.
A bottle or compressor is a common supplier of compressed air. For choosing the right supply, you must know about the bottle’s or compressor’s Cubic Feet per Meter (CFM). Knowing the CFM allows matching it with the level of air and the required cutter’s Pounds per Square Inch (PSI).
Many handheld models utilize normal air. A few users depend on the bottled nitrogen, and not on bottled air for portable models, as it is more economical than that of air. Further, nitrogen is drier than the compressed air and results in lesser oxidation, which is essential for cutting stainless steel.
At times, it can be time consuming and hard to carry bottles of gas around with the tool. Thus, a plasma cutter with an included compressor is a more economical choice for cutting thinner materials and enjoying portability. Compressors make plasma cutters more portable and lighter in weight.
Most plasma cutters feature all desired equipment except for one, which is pressurized air. However, there are models that come with an air compressor; the rest of the models depend on shop air. The exact amount of pressure required tends to differ as per the model as well as the manufacturer.
You need to note that air flow is a critical part of the plasma cutting process. High pressure, clean air passing via the torch’s nozzle increases the precision of the cut as well as expands the lifespan of the consumables.
Apart from dust, even moisture and oil are the foes in a compressed air system. While filtration systems are embedded into the cutter, the air compressor’s quality yet has a significant role to play.
Another problem is humidity in the air, as it condenses into moisture under pressurized and further when emitted from the compressor.
In short, ensure that the compressor at least fulfills the manufacturer’s recommendations. Or else, the cut will not be clean and consumables will burn quite faster than expected.
Inference for You: A single gas flow is preferable for cutting a thin metal and it results in plasma and arc shielding. The single gas flow can be of argon, oxygen, air, nitrogen/hydrogen, or nitrogen. On the other hand, dual gas flow is used for cutting a thicker metal.
Desiccant Air Dryer & Filtration Systems
Consider having a desiccant filter mechanism in your plasma cutter, as it is the most effective way to ensure that the air flowing into the nozzle is dry as well as clean. Such a system is capable of discarding moisture along with any disturbing particles from the air prior to reaching to the torch.
I agree that the filter systems are not economical at all but they can give you more benefits than the amount you tend to pay. These systems pay you back in the short run itself by making you save on replacing consumables. That’s because the frequency of replacement is reduced significantly.
Further, a filter system is also likely to improve the cut’s accuracy. This is critical to have for several CNC applications although any job that needs lean and accurate cuts needs it.
You should consider environment in mind while selecting a plasma cutter. A messy or dirty environment is likely to supply unclean air to your cutter. This is bound to impact the cutting accuracy as well as the cutter’s durability.
Therefore, if you know that your working environment is going to be full of metal shavings and/or heavy dust, choose a plasma cutter that comes with wind tunnel or a built-in fan mechanism. Such a mechanism is exclusively designed to offer better reliability as well as precision.
In the technology of wind tunnel, the cooling air flows via the tool such that the air does not hit any electrical component and that dirt does not settle on them or on a circuit. In case of fan-on-demand, a cooling fan operates when desired for keeping dirt away from the device.
Many modern units come with a few automated functions, of which one is the cooling fan running only when needed. As it indicates, such models are pricier than those without these functions.
Inference for You: It is worth choosing any of the two mechanisms for working in a dirty surrounding.
Control Panel: Indicators and Controls
This is one more important factor to consider while buying a plasma cutter. It is actually the main part of the cutter, as it enables you to operate the device. To ensure ease of use, it is worth considering a model with controls along with other indicators that are easy to read as well as comprehend.
For those who will be using a plasma cutter for the first time, it is extremely critical to comprehend the controls for using the machine. So, if the controls are easy and particular, it becomes easy to use a plasma cutter like a pro, even if you are just a beginner.
For enjoying a greater level of convince, consider a plasma cutter with an embedded consumable compartment. This is usually included on the control panel.
The model you choose must also have a power switch along with a way to set or adjust the current setting as per the metal being cut. Many modern models come with LED indicators that are quite easy to observe, read, and understand what they convey. They are usually on the front panel.
Well, the units with LED indicators are a bit more expensive than those without them. Even those machines that feature precise digital controls are expensive.
You need to know that a few cutters are only for indoor use, while the rest are for outdoor use. Nevertheless, the modern models come with housings due to which they are useable in different conditions.
Such models are a bit more expensive than the less secured ones. However, consider these extra money worthy of investment if you will be working outdoors.
When you buy a plasma cutter, you can consider buying some accessories that are compatible with your model. These accessories further simplify the task of cutting, even if the material to be cut is large. Below are these popular accessories:
- Shield Cup: Affixes to torch handle’s end and controls the intensity along with the magnitude of cutting force.
- Cutting Guides: Aligns a cut to ensure that it is along the desired path.
- Silicone Grease: Increases the lifespan of the O ring on the torch, as it withstands incredible heat and pressure.
- Air Dryer/Regulator: Prevents moisture accumulation in the cooling air around the cut region.
- Cart: Allows easy carry of a heavy model.
- Cutting Table: Is handy for hard-to-move big stuff or objects.
- Circle Cutting Attachment: Affixes to the middle of the tool and allows cutting a circle more easily than your expectations.
- Hose: Links to the tool to the torch. It needs to be long enough to connect the two.
- Protective Gear: Ensures safe cutting with plasma.
When it comes to buying a plasma cutter, it is obvious to look for the most reliable brand. Here are a few such brands to consider: Hobart, Lincoln, Miller, Lotos, Longevity, Super Deal, Everlast, and ESAB.
Step 3: 5 Best Plasma Cutters of 2017
Below is my list of top 5 plasma cutters that I can recommend to anyone. I have shortlisted them, as each of them is reliable and has customer ratings of at least 4 out of 5.
1. Super Deal CUT-50
It is ideal for hobbyists who perform little plasma cutting for metal sheets of varying sizes. It can easily cut a 1/4-inch steel although it is a bit slow. However, it is the most affordable unit in this list. On the down side, it is a Chinese product.
Features: Digital inverter technology, pressure reducing valve, cutting torch, Earth clamp, plasma tip, air regulator, hoop, gas pipe claspers, wire brush, face mask, goggles
- Weight: 25 pounds
- Power Input: 110/220v
- Amperage Output: 20-50A
- Duty Cycle: 60% @ 50A
- Metal Thickness: 1-12 mm
2. Lotos LTP8000 Non-Touch Pilot ArcAir
It is a bit costlier than the Super Deal model, but is yet an affordable one due to the features on offer. It is a compact model offering a comfortable handle for portability. It utilizes safe compressed air for cutting along with a pilot arc torch that ensures efficient cut even if the surface is rusty, painted, or uneven. Slag is also minimal.
Features: IGBT inverter technology for efficient cuts, MOFSET transistor for uniform output on thin metal and high power result on thick metal, pilot arc, high frequency start, contact torch, PAPST advanced German cooling system, air regulator, Earth clamp and cable, air hose connections, air hose
- Weight: 52pounds
- Power Input:220/240v
- Amperage Output:20-80A
- Duty Cycle:60% @ 80A, 100% @ 40A
- Metal Thickness: 1-inch clean cut and 1.5-inch maximum severance cutthickness on copper, stainless steel, brass, mild steel, alloy steel, aluminum, and so on
3. Hobart 500546 Airforce 700i :
It is a bit costlier but is lighter than its predecessor and covers a wide cutting range and several features. It is capable of cutting 3/8- to 5/8-inch thickness of steel via an engine-driven welder and a 240v generator power of 8,000 watts or more. This model is made for more comfort, as it ensures affordable replacement cutting tips and more efficient cooling. It can even endure difficult working environments with a duty cycle of 35% when the temperature is 104 degrees Fahrenheit.
Features: Creative inverter, new ergonomic handheld torch, peak performance under fluctuating input voltage conditions for cleaner and stable cuts, post-flow air cooling for the tip and torch, line voltage compensation, fan on demand, extension cords for expanding work space, power factor correction, cable management strap, thermal overload protection, wind tunnel technology, extra consumables, 230v plug, gas regulator, and built-in gas/air filter
- Weight: 31 pounds
- Power Input: 230v
- Amperage Output: 40A
- Duty Cycle: 50% @ 40A
- Metal Thickness: 5/8-inch rated cut @ 9 IPM and 7/8-inch maximum severance cut on conductive materials
4. Miller Electric Spectrum 375:
It is a compact unit for hobbyists and home users who are looking for portability at its best and efficiency for cutting thin and thick materials. This model is not designed for those who wish to cut thick metals quite frequently. It is costlier than all above models, perhaps because of the different incorporated technologies.
Features:XT30 torch, MVP plugs, heavy-duty clamp, case, extra consumables, shoulder strap, ergonomic handle, auto air regulation for optimal performance, easy to read LED indicators, wind tunnel technology, fan on demand, Auto Fire technology for controlling the pilot arc, three different types of tips, deflector, gouge shield
- Weight:34 lbs
- Power Input: 120/240v
- Amperage Output:14-30A
- Duty Cycle: 20% @ 20A, 35% @ 15A
- Metal Thickness:3/8-inches at 18 IPM and 220v
5. Longevity ForceCut 42i :
It is the costliest unit in this list but is also one of the most portable, travel-friendly, and lightest plasma cutters offering low-cost consumables as well as cutting operation. The incessant pilot arc is effective for cutting painted, expanded, or rusted metals. With the snap of a plug, the adapter quickly switches between 110 and 220 volts.
Features: Auto air regulation, carrying strap, water separation, power factor correction for operation from 90-280v, digital meters, thermal overload protection, CNC ready, IGBT inverter technology, blow back type, Earth clamp, extra consumables, pilot arc technology
- Weight: 34 lbs
- Power Input:110/220v
- Amperage Output: 40A
- Duty Cycle: 40% @ 40A
- Metal Thickness:1-inch thick steel at 220v and 3/8-inch steel at 110v
A plasma cutter is your best friend when it comes to cutting thin to thicker pieces of conductive metals. However, you need to choose it right by considering the aforementioned factors. Overall, ease of use and high quality performance are the most significant factors.
I would recommend looking at the different customer reviews, especially by the experienced ones so that you can get the real picture before investing in it. You can even ask your friends who use plasma cutters.
This is regardless of what your budget is. You should always seek for all probable recommendations and then choose the one that is affordable and reliable (as per your requirements).