How to Choose a Plasma Cutter: A Practical Buying Guide

How to Choose a Plasma Cutter: A Practical Buying Guide

The best plasma cutter for your workshop is the one that cuts your regular material efficiently, works with your available power and air supply, and suits the amount of cutting you do. Start with thickness—but do not choose a machine simply because its advertised maximum exceeds the thickest plate in your workshop. Recommended cutting capacity, severance capacity and piercing capacity describe different capabilities. Understanding those differences helps you avoid buying a machine that can technically separate the material but is too slow for your everyday work. Whether you are buying for fabrication, agricultural repairs, vehicle maintenance or general workshop use, this guide explains how to compare plasma cutters and choose a suitable setup.

What is a plasma cutter?

A plasma cutter uses an electric arc and a high-velocity jet of ionised gas to cut electrically conductive metal. The arc melts the material, while the gas jet removes the molten metal from the cut. Plasma cutting can be used on mild steel, stainless steel, aluminium and other conductive metals. Many portable workshop machines use compressed air. Most require an external compressor, although some models have a compressor built in. Both types still need a suitable electrical supply. For the buyer, the important question is not just whether a plasma cutter can cut a particular metal. It is whether it can cut your usual material and thickness at a useful speed, with an acceptable finish.

How to choose a plasma cutter?

Compare machines in this order:

1. Identify the metals and thicknesses you cut.
2. Compare recommended cutting capacity and the stated cutting speed.
3. Check the electrical supply required by the exact model.
4. Confirm compressed-air flow, pressure and air-quality requirements.
5. Compare duty cycle at the output you expect to use.
6. Check handheld or CNC compatibility.
7. Compare the complete setup cost, including consumables and supporting equipment.

These checks bring together the main requirements identified in manufacturer setup guidance, capacity tables and duty-cycle documentation.

Start with the material you cut most often.

Before looking at machines, write down:

• The metal you cut most frequently.
• Your usual cutting thickness.
• The thickest material you cut regularly.
• The thickest material you only occasionally need to separate.
• Whether cuts start from an exposed edge or require piercing through the plate.

Keep regular work and occasional maximum-thickness work separate.

For example, Hypertherm lists the Powermax45 SYNC at 16 mm at 500 mm/min, 22 mm at 250 mm/min, and 29 mm severance at 125 mm/min. The machine can cut thicker material, but the rated travel speed falls substantially as thickness increases. If you regularly cut 16 mm plate, compare machines on their performance at 16 mm—not simply on the largest thickness in the brochure.

Recommended cut, severance and piercing: what is the difference?

A headline such as “cuts up to 20 mm” does not tell you enough to choose a plasma cutter. You need to know what the rating describes, which material it applies to and the cutting speed involved.

Hypertherm publishes recommended, severance and, where applicable, pierce ratings separately. Its guidance also distinguishes piercing from the cutting that follows, including different height requirements to protect the torch and consumables. When comparing plasma cutters from different manufacturers, check that you are comparing equivalent ratings. A maximum-cut figure should not automatically be treated as the same thing as another manufacturer’s recommended capacity.

What size plasma cutter do I need?

Use the manufacturer’s cutting-capacity figures as a starting point rather than assuming that a particular amperage always cuts a particular thickness. The following table compares selected Hypertherm systems. It is a capacity guide—not confirmation that every package has the same electrical requirements, torch, interface or availability.

These figures come from Hypertherm’s Powermax comparison information. Check the individual model’s cut charts for material, speed and operating conditions. Some systems also have a second recommended thickness at a lower travel speed. For example, the Powermax30 AIR is rated for 8 mm at 500 mm/min and 10 mm at 250 mm/min, with 16 mm severance at 125 mm/min. Describing it only as a “16 mm plasma cutter” would leave out the performance distinction that matters to a buyer.

KWS supplies Hypertherm and Telwin plasma cutters. Our category comparison tables distinguish between manufacturers’ recommended and maximum-cut figures so you can assess the specifications in context. 

Source: Hypertherm Powermax system comparison. Ratings depend on material, cutting speed and operating conditions. Check the individual model’s documentation before purchase.

Browse plasma cutters at KWS.

Is a higher-amp plasma cutter always better?

No. Amperage is important, but it does not describe the machine’s complete cutting performance. Hypertherm explains that cutting power depends on output current and arc voltage. Its duty-cycle guidance also recommends comparing true output power under the stated conditions rather than comparing amps alone.

When comparing machines, ask:

• How quickly does each machine cut my regular material?
• Is the quoted thickness a recommended cut or a severance cut?
• What duty cycle applies at the required output?
• What electrical supply is needed to achieve the published performance?
• What torch and consumables are used?

A higher amperage figure is not, by itself, proof that one machine will cut your work faster or at a lower overall cost.

Can a plasma cutter run on 230V single-phase power?

Yes. Plasma cutters designed for single-phase supplies are available, including portable machines in the KWS range. However, “230V” does not tell you the machine’s required input current, circuit protection or installation requirements. For example, KWS lists the Telwin Technology Plasma 60XT as a 230V single-phase machine. Its 10–60A cutting-output range is separate from the current it draws from the electrical supply.

Before buying, check:

• Supply voltage and phase.
• Required input current.
• Circuit-protection requirements.
• Plug and connection requirements.
• Manufacturer restrictions on extension leads.
• Generator requirements, if applicable.

Follow the exact model’s installation instructions and have a competent electrician confirm supply suitability where necessary. Do not assume that a machine can deliver full output simply because the available socket has the correct voltage.

When should you consider a three-phase plasma cutter?

The KWS range includes larger three-phase machines. Some model families also have different supply configurations, so check the exact product version being quoted rather than relying on the family name alone. This is particularly important if you are comparing an Irish product listing with a brochure or video intended for another market.

Do plasma cutters need an air compressor?

Most portable air plasma cutters require an external compressed-air supply. Models with an integrated compressor are an exception. The Hypertherm Powermax30 AIR contains its own compressor and does not require an external compressor or external air filter for normal operation. KWS also lists the Telwin Technology Plasma 54XT Kompressor with a built-in compressor.

A built-in compressor can simplify a portable setup, but it does not remove the need to compare cutting performance.

Check airflow and pressure together.

The compressor must supply the required airflow at the specified operating pressure. Requirements vary substantially between machines. KWS lists the Telwin Technology Plasma 60XT at 100 litres per minute and 4–5 bar. Hypertherm lists the Powermax125 cutting requirement at 260 litres per minute and 5.9 bar. One compressor specification will not suit every plasma cutter. Ask your supplier to confirm usable delivered airflow at the required pressure, including whether the compressor must support other tools at the same time.

Do not overlook air quality.

For Powermax air plasma systems, Hypertherm recommends a suitably sized compressor and treatment to remove particulate contamination, oil mist and moisture. Its guidance identifies refrigerated drying and filtration as an effective arrangement. Discuss air treatment when choosing the cutter, rather than waiting until the machine arrives.

What does duty cycle mean on a plasma cutter?

Duty cycle describes how long a plasma system can operate within a ten-minute period under specified conditions. For example, a 50% duty cycle means five minutes of operation within that period at the stated test conditions. Read the percentage alongside the output, ambient temperature, input supply and other conditions specified by the manufacture. The Powermax30 AIR illustrates why those conditions matter. Its operator manual lists a 35% duty cycle at 240V and 30A, compared with 20% at 120V and 30A, at an ambient temperature of 40°C.

Match duty cycle to your workload

Consider two workshops cutting the same material thickness:

• A maintenance user makes a short cut, then spends several minutes measuring and positioning the next component.
• A production user makes repeated long cuts with little time between them.

The required operating capacity may be very different. Compare duty cycle at the output you expect to use. A percentage without its operating conditions is an incomplete comparison.

Can a handheld plasma cutter be used on a CNC table?

Some plasma systems support handheld and mechanised applications, but CNC suitability depends on the exact configuration. KWS lists machine-torch packages including Powermax45 SYNC, Powermax65 SYNC and Powermax105 SYNC options. A dedicated machine-torch package is not necessarily interchangeable with a handheld package bearing a similar model name.

Before ordering for a CNC table, confirm:

• Machine-torch compatibility.
• Torch-lead length.
• Machine interface and start-signal requirements.
• Voltage-divider and torch-height-control requirements, where applicable.
• Pierce capacity for your material.
• Availability of suitable cut charts.
• Fume-control arrangements.

Have the plasma supplier and table supplier agree the configuration before purchasing. Do not assume that changing the torch resolves every compatibility requirement.

Why pierce capacity matters for CNC cutting

An edge-start rating is not the same as a pierce rating. Hypertherm publishes them separately and explains that piercing requires different height settings to limit molten-metal splashback. If your parts require internal starts, compare pierce capacity as carefully as headline cutting thickness.

What metals can a plasma cutter cut?

Plasma cutting works on electrically conductive metals, including:

• Mild steel.
• Stainless steel.
• Aluminium.
• Copper.
• Other conductive alloys.

It is not a general-purpose process for non-conductive materials such as wood or plastic. However, a machine’s ability to cut a material does not mean every setup produces the same finish. For example, Hypertherm notes that compressed air can be an economical option for aluminium, but the cut edge may show more oxidation and need cleaning before welding. Gas choice, consumables and operating parameters affect the result. When requesting a recommendation, specify the material and explain what happens after cutting. An edge that will be welded may have different requirements from one that will be painted or left visible.

Plasma cutter or oxy-fuel cutting: which is better?

The answer depends on the material, thickness and workload. Plasma can cut conductive metals including stainless steel and aluminium. Conventional oxy-fuel cutting relies on a chemical reaction with steel and is not effective for cutting stainless steel or aluminium in the same way. Oxy-fuel remains an important option for thick carbon-steel work.

These distinctions follow Hypertherm’s comparison of the processes. Neither process is the best choice for every material and workload. For a mixed-metal workshop, plasma’s ability to cut different conductive metals is particularly useful. For thick carbon-steel work, compare the complete process rather than assuming plasma is automatically the better purchase.

What does a plasma cutter cost to own?

The machine’s purchase price is only part of the budget. Depending on the setup, you may also need an external compressor, air treatment, electrical installation work, consumables, protective equipment and fume control. Manufacturer setup guidance and Irish Safety Guidance show why the cutter should be considered as part of a complete working system.

Compare quotations using the following checklist:

For an Irish business purchase, compare quotations on a consistent VAT basis. Also check what is included: a machine-only quotation is not directly comparable with a complete working package.

Check consumables before buying.

Plasma systems use consumable components, but their arrangement differs by torch and system. Hypertherm’s Guidance distinguishes conventional consumables from cartridge consumables used on compatible systems.

Before ordering, establish:

• Which consumables suit your regular cutting application.
• The correct part numbers.
• What is supplied with the machine.
• Replacement pricing and availability.

Do not assume that consumables are interchangeable because they look similar.

What safety controls are needed for plasma cutting?

Plasma cutting introduces electrical hazards, intense arc light, hot metal, sparks, noise and fumes. Appropriate controls and protective equipment are necessary even for short jobs. Manufacturer guidance identifies cutting gloves, correctly shaded eye and face protection, flame-resistant clothing and suitable footwear as important protective measures. Hearing protection may also be required. Use protection appropriate to the machine, output and application.

Control cutting fumes at source.

Irish Health and Safety Authority guidance explains that plasma-cutting fume comes from the material being cut, and its composition depends on that material. Its technical guidance identifies local exhaust ventilation, such as a downdraught table, as a control for open-workshop cutting. Respiratory protection may also be needed where engineering controls do not adequately control exposure. Coated or contaminated material requires particular attention because coatings can introduce additional hazards. An open door is not evidence that exposure is adequately controlled; assess the process, material and workplace conditions.

Never cut unsafe containers

Do not cut closed or pressurised containers. Containers that have held combustible, toxic or reactive materials require assessment and clearance by a qualified person before hot work. This buying guide does not replace operator training, a workplace risk assessment or the machine’s safety instructions.

Plasma cutter buying checklist

Before asking for a quotation, gather the following information:

These details give your supplier a clearer basis for recommending a suitable machine than amperage or maximum thickness alone.

Frequently asked questions about plasma cutters

What is the differenc between a plasma cutter and a welder?

A plasma cutter removes material to make a cut. Welding joins materials. Although both processes can use an electric arc, a plasma-cutting system is not automatically a welding machine.

Can a plasma cutter cut stainless steel and aluminium?

Yes. Both are electrically conductive and can be plasma cut. Use the settings, consumables and process guidance appropriate to the material and finish required.

Do I need bottled gas for a plasma cutter?

Not necessarily. Many portable air plasma systems use compressed air. Some need an external compressor, while machines such as the Powermax30 AIR have one built in. Other plasma processes use different gases, so follow the specification for your system

Is maximum cutting thickness the same as recommended cutting thickness?

No. Recommended and severance figures describe different performance levels. The Powermax45 SYNC, for example, is rated at 16 mm at 500 mm/min and 29 mm severance at 125 mm/min.

Is a higher-amp plasma cutter always better?

No. Compare cutting performance, output power, duty cycle and supply requirements. Amperage alone does not describe the machine’s complete capability.

Can I run a plasma cutter from a generator?

Some systems can operate from an appropriately sized generator. Check the generator requirements in the exact model’s documentation rather than choosing a generator from the machine’s cutting-output amperage.

Which plasma cutter is best for a small workshop?

There is no single best model for every small workshop. Start with your regular material thickness, available electrical supply, air requirements and workload. A built-in compressor can simplify the setup, but its capacity and duty cycle still need to match the job.

Get help choosing a plasma cutter in Ireland

Kilkenny Welding Supplies supplies Hypertherm and Telwin plasma cutters, with support through our Kilkenny and Portlaoise depots. Our range includes portable machines, built-in-compressor options and dedicated machine-torch packages. Tell us what you cut, how thick it is, what power and air supplies you have, and whether you need handheld or CNC operation.

Already know your requirements? Browse our plasma cutters, or contact KWS to check the right power and air setup.”, or call Kilkenny on 056 7729949 or Portlaoise on 057 8643557 to discuss your needs.