A plasma cutter is a tool used for cutting metal sheets such as steel or aluminum. Instead of using a saw, this tool implements electricity in combination with pressurized air to create an extremely hot plasma torch. It is available in many different variants and specifications, but to get the best plasma cutter for your needs, please consider the following factors.
There are two different types of plasma cutter including big industrial-grade model and the portable hand-held one. The former usually requires 220V power source to produce an output between 50 and 80 amps. Large model can easily cut through up to 2-inches sheet of metal. A small portable plasma cutter uses 110V power source and generates output power of 12 to 35 amps. You can use this for home DIY projects to cut through up to 0.5cm thick metal material.
A more sophisticated model has built-in inverter. This particular type is usually more expensive, but you get the advantage of portability. It takes DC power and feeds it through the inverter from around 10 kHz to 200 kHz. Higher switching frequencies give greater transformer efficiencies and therefore manufacturers are able to make smaller overall dimension of the tool. Those who offer mobile services usually choose this model. It typically requires more than 2 kilowatts of power to operate.
A full set of the best plasma cutter may include a variety of accessories, preventing you from purchasing more equipment to get started. However, depending on the brand and models, a plasma cutter may come as a stand-alone product, which means you have to purchase additional accessories before you can actually start operating it safely. Some of the most common accessories used with or attached to a plasma cutter are as follows.
- Electrodes: it is the hardware that starts the arc and sends it to metals work piece. Electrodes and the housing need frequent replacements.
- Cutting guides: it has similar functions to lasers circular saws. A cutting guide helps to align the cutting either in straight line or any desired path.
- Plasma torch: this accessory is attached to the end of plasma cutter tool. It controls the plasma and does the actual cutting function.
- Cart: non-portable models for high-performance cutting are usually heavy, but you can purchase a cart to make it easy for you to move it around the workplace.
4. Gas Supply
Older models of plasma cutter used two types of gas supplies including nitrogen (as the primary supply) and CO2 (as the secondary one). Such configuration requires bulk containers which can be expensive as well. Modern plasma cutter can use only clean dry air to create plasma and cool the torch at the same time. Many hand-held plasma cutters have on-board air compressors to improve portability value. Shop air is also inexpensive, but it is intended mostly to cut thin stainless steel and aluminum.
The torch on any plasma cutter contains the same things as follows:
- An electrode to start the arc and transfer it to metal material
- Gas distributor to stabilize the flow of plasma
- A nozzle to control or focus the plasma output
There are two types of torches available including HF (high-frequency) and Contact Start. High frequency is used in many hand-held plasma cutters thanks to its efficient transformers and small size. There is also no moving part inside the torch, making it relatively dependable. That being said, high-frequency torch requires regular maintenance to prevent hard-starting issues. In most cases, high-frequencies may interfere with electronic equipment such as computer and audio player. If you are working in a place where there are plenty of electronic appliances, you may want to avoid using this model.
On the other hand, Contact Start torch generates less electrical noise, but a plasma cutter with such torch may not be as portable as its HF counterpart. It starts the arc by allowing direct contact between electrode and nozzle to create a short circuit.
6. Thickness of the metal
Apart from all the technical specifications of the plasma cutter itself, you will also want to consider the thickness of metal material to cut. As a rule of thumb, high amperage means better cutting power for thicker metals. In case you mostly work with thin aluminum or steel, a low amperage one should be sufficient. The best plasma cutter is not necessarily the most powerful because it entirely depends on your needs. It is better to use low amperage for non-demanding application than purchasing the more expensive high-amperage model.
7. Cutting speed
Any product description of plasma cutter should provide information about maximum cutting speed, usually measured in inches-per-minute. Higher amperage means faster cutting. In real world performance, you will also need to consider the duty cycles of the plasma cutter. The terms “duty cycle” means the tool’s ability to perform continuous cutting before it overheats. Duty cycle is measured in percentage of 10-minute. For example, a plasma cutter with 70% duty cycle of 60A means it will do a continuous cutting performance with 60A power for 7 out of 10-minute period.
Working environment is another important consideration. Plasma cutter can be bulky and heavy tool or lightweight and portable. In case you need to move around and carry the plasma cutter, you will need a hand-held model to make your job easier. If you have to work with heavier tool, you may want to purchase trolley-mounted unit to easily carry the tool anywhere. You may also need a trolley that offers storage space for cables, torches, and other accessories.
Manufacturer’s warranty has always been one of the most important factors to consider when purchasing anything including plasma cutter. Not all plasma cutters are created equal, but it is safe to assume that longer warranty means better durability. A budget-friendly plasma cutter may only offer up to 1 year warranty, but the more expensive models can offer you up to 5 years warranty for parts and labor. However, the best plasma cutter for your needs is not always the model that offers the longest warranty period.
10. Customer reviews
Despite all the impressive specifications and tempting warranty offers, you will need to read customer reviews before purchasing the tool. Better customer reviews also mean better product rating. Although a different store may have different rating scheme, your best bet is to purchase a plasma cutter with at least better-than-half of the perfect score.
Plasma cutter is now widely available in both offline and online stores. Each model is designed to do specific tasks with its own advantages and limitations. Once again, the best plasma cutter is not necessarily the most expensive, but it is the one that fits your bill yet it delivers the performance you want without any frill.