Have you ever asked yourself why cuts sometimes differ? Some cuts are wider on the top and narrow on the bottom and the other way around. Or dross is stuck underneath a sheet after the cutting process. What are the reasons for that? How can you prepare a process to avoid all of this which mostly needs additional rework and thus time and costs? This article will give you an insight to this topic. You will learn how to read the cut and how to improve plasma arc cutting quality.
Based on Thermacut’s experience with plasma cutting systems and consumables used in demanding industrial environments, cut quality is most often affected by several factors. Let´s focus on the interpretation of key factors that affect plasma arc cut quality.
The main cut quality characteristics are bevel angle, lag lines, dross levels and dimensional accuracy, they are addressed individually so that the influence of change can be assessed.
Cut angle
What is the ideal cut angle? An acceptable one is one whose average bevel angle on all four sides is less than 4°. You will mostly struggle with negative or positive cut angles, or a combination of both.
Picture: Negative and positiv cut angle
Negative cut angle: Top dimension is greater than the bottom dimension.
The main causes are typically low torch to workpiece distance, misaligned torch, bent or warped material, slow cutting speed, excessive power, worn or damaged consumables.
Solution: Increase the arc voltage to raise the torch or increase the cutting speed to square up the cut.
Positive cut angle: Top dimension is less than the bottom dimension
The main causes are typically high torch to workpiece distance, misaligned torch, bent or warped material, fast cutting speed, worn or damaged consumables.
Solution: Decrease the arc voltage to lower the torch or increase the cutting speed to square up the cut.
Combination of positive and negative cut angle
This can be the result of the cut speed being too fast or a malfunction of the torch height control.
Lag lines & Dross levels
Looking closely at the lag lines, they are the ripples present on the edge of the cut that show the variation in cutting speed. Reading the lag lines on a cut surface is an excellent way to determine proper cutting speed. Normal lag lines are curved and slanted at about 15° and the cut is dross-free.
Picture: Good quality stainless steel cut
Picture: Good quality aluminum cut
Dross is a by-product of the cutting process. It is the undesirable material that remains attached to the part. In most cases, dross can be reduced or eliminated with a correct torch and cutting parameter set-up.
The appearance of dross is relevant to the cutting speed. Using the correct cutting speed can deliver a dross free cut. The proper set up of operation data for a given material thickness is noted in the mid-range of cut chart.
Picture: Low and High speed dross
Low speed dross
Globular dross that forms in large deposits. It has low adhesion properties and is quite easy to remove, in sizable pieces.
High speed dross
Thin sharp-edged material that welds itself to the bottom edge of the workpiece. It is difficult to remove, normally requiring grinding or other 2nd ops dressing. There are clearly defined “S” shaped lag lines shown on the cut edge of the piece.
Picture: Top dross
Top dross (spatter)
Top dross or spatter can form on the top edges of the workpiece and parent material. It is normally formed when the consumables are spent, incorrect torch height or where the cut speed is too fast. The dross is typically easy to remove.
Intermittent (non-continuous) dross
Worn or spent consumables can contribute to the formation of intermittent dross along the top or bottom edges of the cut piece.
Other factors that contribute to the formation of surface dross are, temperature of parent material, heavily mill scaled or corroded material and high carbon alloys.
Dimensional accuracy (Kerf width)
What does the kerf width tell us? Kerf is the void created by the cutting process (or the volume of material removed).
Kerf width is critical to the dimensional accuracy of the part. A wider kerf is typically caused with a slower cut speed or excessive power. The kerf width is equal to 1.5 – 2.0 x nozzle orifice diameter. It is essential that the parameters of the cut charts are adhered to. Cutting performance can differ across installations and material composition, systems have an in-built facility that enables the override of the cut chart parameters.
Picture:Cut chart parametres
Final recommendation
Cutting issues? Prior to making any alterations, check the condition of the consumables, check the part numbers are correct and the cutting variables match the manufacturers recommended settings.
Small adjustments to the cut charts settings may be needed to compensate for a change in material quality, material temperature or a specific material type.
Make small incremental changes when adjusting settings. Adjust the Arc Voltage up or down in 2-volt steps as required. Increase or decrease the cutting speed by 5% until the cut quality improves.
Using the recommended cut chart values for cutting speed and arc voltage maximises cutting performance.
The cut chart variables are interdependent, changing one setting affects all others and may influence the overall cut quality.
We hope the article was useful for you. We also recommend another article related to the theme, Enhancing your plasma cutting quality. If you needed any further help, please do not hesitate to contact us at the following email: support@thermacut.cz
Text: Thermacut, k. s., Photo: archive of Thermacut, k. s.
In plasma cutting, the biggest cost drivers usually aren’t the obvious ones. Most fabricators aren’t losing money on major failures—they’re losing it in small, everyday inefficiencies that add up over time. How a power supply is set up, how torches & consumables are selected, and when they’re replaced all have a direct impact on cost per cut, cut quality, and overall productivity. The challenge is that many of these decisions come down to habits built into daily operations. Understanding where those losses happen is the first step to reducing them.
The Hidden Cost of “Running Hot”
It’s a common assumption that running at maximum amperage means maximum productivity. On paper, it makes sense—more power should mean faster cuts. In practice, it often creates more problems than it solves.
Running at full output increases heat input, which can widen the kerf, reduce edge quality, and make it harder to hold tight tolerances – especially on thinner materials or detailed parts. You may end up spending more time on cleanup, and consumables tend to wear faster under the added thermal load. The most cost-effective setup isn’t the most aggressive – it’s the most consistent. Dialing in the right amperage, speed, and cut height typically leads to better cut quality and a lower cost per part.
Consumable Mismatch: A Costly Misconception
Improper consumable selection is one of the most common and misunderstood issues in plasma cutting. A frequent assumption is that using a higher amperage nozzle at a lower output will extend consumable life. In reality, it usually does the opposite. When the amperage and consumables don’t match, arc density drops. That less-focused arc can slow cut speeds, increase heat input, and reduce overall consumable life.
Instead of improving efficiency, it often leads to:
Lower cut quality
Slower production speed
More dross and secondary cleanup
Shorter consumable life
Matching consumables to the actual operating amperage is key. It helps maintain proper arc characteristics, consistent cut quality, and more predictable performance.
The Replacement Timing Problem
When consumables get replaced, it can have a bigger impact on cost than most shops realize. Some operators run consumables until complete failure to get every last bit of life. While that seems cost-effective, it often leads to poor cut quality, scrap, or even torch damage. Others replace consumables too early to avoid the risk of a failure mid-cut – especially on CNC tables, where stopping a program can interrupt an entire nest. In those cases, usable life is often left on the table.
The reality is more nuanced. Not all consumables wear at the same rate. Electrodes and nozzles typically wear together, while swirl rings and retaining caps often last longer. Replacing everything at once, every time, can drive up costs unnecessarily.
Maintenance: The Overlooked Cost Driver
Even high-quality consumables won’t perform well in a poorly maintained system. Contamination, inconsistent cooling, and general wear in the torch or power supply can all reduce performance and shorten consumable life. Something as simple as handling consumables with dirty hands can introduce oil or debris into the system. Lubrication is another detail that’s easy to overlook. A small amount of silicone lubricant helps with sealing, but too much can interfere with gas flow inside the consumable stack. These aren’t major issues on their own but over time, they can have a real impact on performance and cost.
How Aftermarket Consumables Change the Equation
Consumables are a recurring expense, so even small improvements can make a noticeable difference.High-quality aftermarket consumables are designed to meet OEM performance standards with cut quality and lifespan, while offering a lower cost.Savings of 20–30% are common, depending on the application and setup. Beyond cost, aftermarket options can also give operators more flexibility. With the right setup, it’s often possible to get more usable life out of consumables without sacrificing cut quality.
The THERMACUT® Advantage
Thermacut aftermarket consumables are designed to balance performance and cost efficiency. Unlike cartridge-based systems that require full replacement, Thermacut solutions allow individual components to be replaced as needed. This helps reduce unnecessary waste and gives operators more control over consumable usage
THERMACUT designs are engineered to:
Deliver stable arc performance and consistent cut quality
Compete with OEM consumables in performance
Support a longer usable life in many applications
The goal is a more efficient cutting process and a lower overall cost per cut.
Getting the Most Out of Your Setup
Even with the right consumables, results depend on how they’re used. One common issue is mixing consumable brands within the same torch. This can affect fit, alignment, and overall performance. For best results, consumables should be used as a matched set.
Another detail that’s often missed is updating components like the water tube or cooling tube when switching to aftermarket parts. Overlooking this can limit performance. These may seem like small details, but they can make a noticeable difference on the shop floor.
A More Cost-Efficient Way to Cut
Reducing cutting costs isn’t about one big change – it’s about tightening up the entire process. Small adjustments in setup, consumable selection, maintenance, and replacement timing can all reduce cost per cut. When combined with the right consumables, the savings add up quickly. For fabricators looking to stay competitive, it comes down to better habits, better setup, and more informed decisions.
Are aftermarket plasma cutting consumables worth it?
In today’s manufacturing landscape, efficiency and cost-effectiveness are paramount. One choice that manufacturers and business owners face is either to choose high priced OEM consumables, or to source their parts elsewhere. High-quality aftermarket plasma cutting consumables can reduce operating costs while maintaining cutting performance. The actual savings depend on consumable design, manufacturing quality and application.This blog explores the cost-saving benefits and vital role that aftermarket consumables play in precision cutting.
Cost-Effective Solutions
Aftermarket consumables offer a lower-cost alternative to OEM parts, without compromising on quality.
Here are some benefits:
● Lower Initial Investment: Aftermarket consumables provide similar quality at a lower cost, helping businesses better preserve their budgets.
● Extended Lifespan: Replacement parts suitable for OEM machines ensure reliable performance and a reduction in maintenance costs.
● Customized Solutions: Aftermarket suppliers offer personalized support and customization, optimizing cost-efficiency for the specific needs of your systems, regardless of the brand.
● The Role of Aftermarket Consumables in Precision Cutting Applications
● Precision cutting requires accuracy, consistency, and reliability. Aftermarket consumables enhance cutting systems in several ways:
– Consistent Cut Quality: Engineered for precision, they ensure uniform cuts, meeting stringent tolerances.
– Enhanced Productivity: They reduce the need for manual adjustments and downtime, increasing efficiency and lowering production costs.
– Cost-Effective Maintenance: Offering an alternative to OEM parts, they help maintain cutting systems without high costs.
Thermacut® Aftermarket Consumables: Your Reliable Partner
Thermacut® provides premium replacement parts for plasma, laser, and oxy-fuel cutting systems. They offer a wide range of consumables compatible with major OEM brands like Hypertherm®, ESAB®, and Kjellberg®.
Replacement Parts
Thermacut® offers exceptional replacement parts to keep systems running smoothly without the need for new machines. Fill out the contact form below to find and quickly receive the parts you need. In conclusion, aftermarket consumables like those from Thermacut® provide significant value by enhancing performance and saving costs, making them essential for achieving manufacturing excellence.
Unlock superior cutting performance with Thermacut’s premium consumables. For more information, contact sales@thermacut.com today!
Text: Thermacut, k. s., Photo: archive of Thermacut, k. s.
How to reduce exposure to fumes during thermal cutting
You cannot make an omelet without cracking eggs – or release harmful gases and fumes. Depending on the base material and the gas used, plasma, laser, or oxyfuel cutting processes release extremely fine particles of zinc, lead, cadmium, chromium, beryllium, and other constituents into the environment. Some of these are highly harmful to health and can cause serious illnesses in humans. This makes it all the more important to avoid inhaling any released fumes when cutting sheet metal. There are various precautionary measures and solutions for this, which we would like to outline here
Parameters influencing fume gas development
The composition and intensity of the cutting fumes depend on various parameters:
Material composition of the material to be cut
Cutting method (plasma, laser, or oxyfuel cutting)
Sheet thickness or material thickness
Fuel gas used (plasma gas, nitrogen, compressed air)
Cutting gas pressure
Cutting speed and cutting length
Looking more closely at the parameters, the composition of the base material plays the most important role. Its components primarily determine the chemical composition of the particles released during cutting.
During thermal cutting, the particles of these dusts are somewhat larger than those produced during thermal joining (welding), but they are still fine enough to enter the human lungs. This makes them hazardous to health and, depending on their components, can even cause cancer. During laser cutting, the released particles are even smaller or finer than during plasma or oxyfuel cutting due to the high energy density of this process and can penetrate cell walls.
Source:European Welding Association (EWA), Technical Committee „Health and safety equipment“ (TC HSE), information paper, draft as per 03/2024 „Introduction in methods of prevention and extraction of welding fume“
In addition to the fine dust, so-called nitrous gases such as nitrogen oxide are produced. These are respiratory poisons with irritating and corrosive effects and can cause lung damage (pulmonary edema) even 24 hours after inhalation.
Each of the cutting processes is complex and poses its own unique hazards, which we won’t discuss in detail in this article. Instead, we want to focus on solutions for reducing exposure to cutting fumes. Well, how to reduce exposure to fumes during thermal cutting?
Fact check on site
If you only cut components occasionally, you’ll work under different conditions than if you work shifts processing tons of sheet metal. Even though you often read that natural ventilation, such as regularly opening the shop door, is sufficient for occasional thermal cutting, you must ensure you have adequate PPE (personal protective equipment). This includes, at a minimum, a ventilated helmet.
If thermal cutting is your regular daily activity, you definitely need a well-designed industrial air cleaning system that fits your needs. There are many customized solutions available. In that article, we would like to introduce to you some of them.
Reducing cutting fumes through the process
Similar to welding, you can adjust the parameters for cutting to reduce emissions from the cutting process. For example, using a 2.4 mm cutting nozzle and 150 amps allows you to work quickly. However, this creates more emissions than cutting with a 1 mm cutting nozzle and 80 amps. The joint is narrower, and the emissions are lower.
Affection of process gases
Process gases also affect the formation of fumes and dust during cutting. Laser cutting produces the least amount of process gas. This cutting process is primarily used for thin sheets less than 10 mm thickness. However, there are now also cutting lasers that can cut sheets with up to 60 mm thickness. Due to the radiation, laser cutting must always be carried out safely and isolated from the surrounding environment by a closed housing. It must be 100 percent impossible for reflections to unintentionally deflect the laser beams. A laser cutting head attached to a robot is only permitted in an enclosed space that cannot be entered during the activity.
Plasma cutting often requires two process gases: the plasma gas, which transfers electrical energy to the workpiece and melts the material. The second is the so-called shield gas, which acts as a process gas to blow out the melted material. If compressed air is used as the shield gas, harmful gases are also produced: nitrogen monoxide and nitrogen dioxide. These are also called NOx, i.e., gaseous compounds of nitrogen and oxygen. By using pure nitrogen as shield gas, you can prevent the formation of harmful NOx because the plasma gas does not contain oxygen as a reactant.
You can also use argon or argon-hydrogen, for example, to reduce emissions. It’s important that the nitrogen doesn’t have oxygen available as a reactant.
Oxyfuel cutting – also known as autogenous cutting – is primarily used for cutting structural steel, especially unalloyed and low-alloy steels. Acetylene, propane as well as propane-butane are used as the fuel gas. Acetylene has a narcotic effect on humans if inhaled.
Emissions can never be completely eliminated, so fume extraction during cutting is the best way to protect employee health. When cutting sheet metal in the workshop, cutting tables with the possibility to extract fumes and water tables offer the best protection. Both options are also highly efficient.
Cutting tables with integrated extraction
The closer the extraction system is to the process, the more emissions can be directly captured. In thermal joining (welding), this is referred to as extraction at the source, where a special extraction torch directly captures the resulting, upward-rising fumes. During thermal cutting, the emissions are almost exclusively blown downwards, i.e., beneath the workpiece. Gases only escape upward during ignition or when piercing the cut. For this reason, extracting the cutting fumes via the cutting table is recommended.
Cutting table principle with integrated extraction
Picture: Downdraft cutting table, front and side view
Cutting tables with integrated extraction systems (downdraft table) are usually quite large. To ensure the most efficient extraction, the cutting tables are further divided into segments (image right, side view). Using a button, for example, the cutting torch activates the opening of the extraction area directly below. This allows for more efficient extraction at specific points, as extraction is only active in the segment over which the cutting torch is currently positioned.
The slag produced during thermal cutting drops into the slag container. Sparks drawn in cool on the side metal sheets and fall down as well. The gaseous emissions are channeled into the extraction duct (see front view, left image) and conveyed through a pipeline to the filter system.
With a water cutting table, the jet that shoots downward during cutting is trapped in a water bed. Slag and coarse particles naturally drop into the water basin. A water cutting table is filled with water to approximately 20 mm below the bottom edge of the workpiece. Naturally, a small amount of flue gas can also escape through the small gap between the cutting grid and the water surface.
The efficiency of an extraction table with dry extraction is higher than that of a water cutting table. If small sheets of metal need to be cut, the efficiency of the extraction table can be increased even further by covering the cutting grid with additional sheets. A water cutting table does not require an additional filtration system, but the water must be continuously “treated” with chemical additives, and the contaminated water must be repeatedly disposed of. Depending on the size of the table, an additional 800 to 1,000 liters of water are added as a weight component, which must be considered when selecting a location. Depending on the on-site conditions, a water extraction table is a simple solution.
Recommendations for water cutting tables HERR® water extraction table 1,600 x 3,200 mm of the CT-PORW series – solution for portable cutting systems, ideally suited for EX-TRACK® CNC cutting system Details: https://ex-track.com/herr-water-table-1600-3200/
The operating principle of a manual cutting table is similar to that of a large cutting table with extraction. However, due to the small cutting surface, the table is no longer divided into individual sections. The material is placed on the cutting grid and cut. Any sparks and slag that are created fall directly onto the cutting grid and are collected, preventing them from being sucked into the extraction system. The light gaseous particles are captured by the slots in the extraction pipe and from there transported via the pipe system to the filter system.
The particles and fumes emitted from the cutting table are directed to the extraction filter system (see illustration on the left) and captured in the filters. The air inlet can also be opened downwards if required. Baffle plates are installed directly behind the inlet. These prevent sparks or larger particles from damaging the filters. Such larger particles directly drop into the collection box and are captured there.
Picture: Filtration system – The right image shows a cross-section through the filter and its flow path.
Depending on local regulations, the purified air is either discharged directly into the environment or vented outside via the existing exhaust system. The most commonly used filter systems for cutting are low-vacuum systems. These offer a high volume flow at low static pressure.
Is a filter efficiency of 99.99 % sufficient for particle sizes ≥ 0.5 µm?
The direct answer to this question is: no. Reason: 98.90 % of all particles are < 0.4 µm in size. This means that a maximum of 1.1 % of the total particle volume is captured in the “coarse” filter. For a particle size of ≥ 0.5 µm, only < 10 % of all particles can be captured with a filter efficiency of 99.99 %.
Our tip: Filter cartridges certified according to DIN 1822 / ISO 29463
Make sure your filter system also captures particles smaller than 0.4 µm. Filter cartridges certified according to DIN 1822 / ISO 29463 meet the requirements for this particle size. These filters are often also referred to as filter for suspended particles. Filters of this type must then meet at least filter class E10. HERR® filter systems comply with filter class E11.
Recommendation for efficient filter systems: 880 series from HERR® with 2 filters à 20 m2 filter surface – very compact, lightweight and highly efficient extraction system, suitable for PorVent cutting table Details: https://ex-track.com/central-extraction-system/
Final recommendations
The fumes produced during cutting are harmful to health and must be prevented from entering the human respiratory tract. Cutting tables with integrated extraction offer the most efficient solution.
Whether a cutting table with dry extraction and a connected filter system or a water table is chosen depends on local conditions and individual preferences.
The most important thing is that the emissions do not pose a toxic load to people or the environment.
Pro Guide: How to Get Clean Straight and Circular Cuts
When it comes to plasma cutting, a lot of things can affect the final cut quality — amperage, torch height, cutting speed, and even the state of your consumables. We’ve already covered these topics in more detail in our earlier posts, Enhancing your plasma cutting qualityor Reading the cut. This time, we’ll focus on the essential pre-cutting checks and walk you through a practical cutting demonstration to help you achieve cleaner, more consistent results right from the start.What cutting technique should you choose to achieve the best results? We will advise you in the following paragraphs.
Prior to start cutting, visually check power cable and work leads for damage. After that check also torch body, connector pins, leads and safety trigger cap. As a third step it is important to choose the right set of consumables and if already used for possible damage, or wear before another use. All the steps are clearly shown in the video below. Do not forget to connect work leads to the material to be cut. Once the installation is complete, you can start cutting.
Video:Cutting system installation and first run. This is an illustrative video only. The torch design shown in the video is from the 1st generation and has been upgraded. The single steps remain the same.
Hand torch cutting technique
Avoid unnecessary firing of the torch, each firing of the torch reduces the lifetime of the electrode and nozzle.
When cutting, ensure the arc spray exits the underside of the workpiece. Incomplete severance is indicated by an upward arc spray. This can be caused by the following: excessive travel speed, incorrect power settings or gas pressure settings, or bad condition of consumables. Hold the torch vertically and watch the arc while cutting along the line.
Always use shielded consumables.
Make light contact between the shield and the workpiece, pull the torch at a steady travel speed.
For straight line/bevel cutting, use a straight edge as a guide.
Pulling the torch gives better control compared to pushing.
For cutting thin material, reduce the amperage to the optimum to achieve the highest cut quality.
The appearance of dross is relevant to the cutting speed. Using the correct cutting speed can deliver a dross free cut. The proper set up of operation data for a given material thickness is noted in the mid-range of cut chart.
Picture: Hand plasma cutting torch FHT-EX® 105RTXH
Straight cutting – cut direction
The compressed air in the torch swirls around the electrode inside the plasma chamber helping the plasma arc constriction and part of the reason for that is to get a straight cut. However, you really get a straight cut more on one side of the arc than on the other. On the most plasma cutting machines it is on the right size, so check rather twice the cut direction the torch is going.
Picture: Choosing the right cut direction
Circle cutting technique
First, prepare the table for cutting (the table differs from the classic workshop table). Place the template and draw the openings onto the metal sheet. You can also use the circle cutting guide kit to achieve perfectly round circles. Secure the template with clamps.
Set the power supply to the appropriate cutting parameters according to the material type and thickness to be cut – more information you can find in the operation manual.
For a repeatable circle cutting we recommend using some metal template or use a circle cutting guide kit, which makes work easier.
Video: Cuttingcircles with the EX-TRAFIRE® 30Hplasma cutting system
Picture: Hand plasma cuttingwith circle cutting guide kit
Plasma tip: Orifice size vs amperage
“You should increase the cutting current in line with the thickness of the material you are cutting. The same applies to the appropriate consumables that correspond with the cutting current. The set of nozzle, swirl ring and electrode is especially important.”
Final recommendations
Cutting issues? Prior to making any alterations, check the condition of the consumables, check the part numbers are correct and the cutting variables match the manufacturers recommended settings.
Small adjustments to the cut charts settings may be needed to compensate for a change in material quality, material temperature or a specific material type.
Make small incremental changes when adjusting settings.
Using the recommended cut chart values for cutting speed and arc voltage maximises cutting performance.
The cut chart variables are interdependent, changing one setting affects all others and may influence the overall cut quality.
Plasma cutting system: EX-TRAFIRE® 55SD up to 55 A
The EX-TRAFIRE® 55SD three-phase plasma cutter, which we are presenting here, is a handheld cutting system with the FHT-EX® 105RTX torch, which is available in lengths of 8 or 15 metres. It also features an ergonomic torch handle which reduces fatigue during long-term use. The system is compact and highly flexible for cutting in hard-to-reach places. It is particularly suitable for cutting sheet metal up to a thickness of 30 mm while providing sufficient power reserve.
Consumables used
We hope the article was useful for you. We also recommend another article related to the theme, Enhancing your plasma cutting quality. If you needed any further help, please do not hesitate to contact us at the following email: support@thermacut.cz
Text: Thermacut, k. s., Photo: archive of Thermacut, k. s.
The shipbuilding and offshore industries are known for their complex and demanding fabrication requirements. With tight deadlines and high standards for quality and safety, yards and fabricators must rely on efficient and precise cutting methods to stay competitive. Plasma cutting has become an essential tool in these industries, offering a fast, accurate, and cost-effective way to cut a variety of materials.
Applications of Plasma Cutting in Shipyards and Offshore
Plasma cutting is used extensively in shipyards and offshore fabrication for a range of applications, including:
Hull fabrication Plasma cutting is used to cut steel plates for hull construction, allowing for fast and accurate production of complex shapes and designs.
Pipe fabrication Plasma cutting is used to cut pipes for offshore platforms, process systems, and other applications, enabling precise cutting of complex pipe profiles.
Structural fabrication Plasma cutting is used to cut steel beams, angles, and other structural components for offshore platforms, jackets, and other structures.
Repair and maintenance Plasma cutting is used for repair and maintenance tasks, such as cutting out damaged or corroded sections of hulls or pipes.
Benefits of Plasma Cutting in Shipyards and Offshore
The use of plasma cutting in shipyards and offshore fabrication offers several benefits, including:
Increased productivity Plasma cutting is significantly faster than traditional cutting methods, allowing yards and fabricators to meet tight deadlines and improve throughput.
Improved accuracy Plasma cutting enables precise cutting of complex shapes and designs, reducing errors and rework.
Reduced costs Plasma cutting can help reduce costs by minimizing waste, reducing labor requirements, and enabling the use of thinner materials.
Enhanced safety Plasma cutting is a relatively safe process, reducing the risk of injury and accidents compared to traditional cutting methods.
Challenges and Considerations
While plasma cutting offers many benefits, there are also challenges and considerations to be aware of:
Material thickness and type Plasma cutting is best suited for cutting thinner materials (up to 2-3 inches). Thicker materials may require other cutting methods.
Cut quality and precision Plasma cutting can produce high-quality cuts, but precision and accuracy depend on factors like machine calibration, operator skill, and material type.
Safety precautions Plasma cutting requires proper safety precautions, including personal protective equipment (PPE), ventilation, and fire suppression systems
Cutting Solutions for Shipbuilding and Repair
For shipbuilders and repairers, cutting thick-walled plates without distortion is a significant challenge. Here at THERMACUT®, we offer a range of cutting solutions that cater to various needs, from manual and mechanized to automated cutting processes.
EX-TRAFIRE® air plasma cutting systems can handle thick plates, including non-alloy and low-alloy steel up to 50 mm thickness (in special applications separation cuts up to 65 mm are possible), making them suitable for constructing decks, bulkheads, and foundation structures of drilling rigs, wind power plants, and ships.
Conclusion
Plasma cutting plays a vital role in shipyards and offshore fabrication, offering a fast, accurate, and cost-effective way to cut a variety of materials. By understanding the applications, benefits, and challenges of plasma cutting, yards and fabricators can unlock improved productivity, efficiency, and safety in their operations.
To learn more about how THERMACUT® cutting solutions can benefit your shipbuilding or repair operations, contact our sales team. Thank you for reading the article.
Text: Thermacut, k. s., Photo: archive of Thermacut, k. s.
Achieving top-notch cut quality with plasma cutting involves understanding the main factors that impact the results. In this blog guide, we’ll explore these crucial elements to help you get the best possible cut every time.
The 7 Key Factors:
Amperage (Cutting Current)
Gases Used for Plasma Cutting
Arc Voltage
Torch Height
Cutting Speed
Kerf Width
1. Amperage: The Power Player
Amperage measures the flow of electrons in an electrical circuit. Higher current levels can reduce dross (the unwanted material that forms on the edge of a cut) for a given material thickness. For instance:
Bonus tip: Lower current consumables generally last longer, especially when cutting with oxygen.
To ensure optimal amperage performance, it’s also essential to maintain a clean and dry air supply system, with regular checks on air quality, gas quality, and CFM (cubic feet per minute) flow rate.
2. Choosing the Right Gases
The purity of gases used in plasma cutting is critical for maintaining cut quality and consumable life. Here’s a quick guide:
Oxygen (O2) and Nitrogen (N2): O2 at 99.5% purity, N2 at 99.99%.
Argon-Hydrogen (H35) and Nitrogen-Hydrogen (N5): H35 at 99.995% purity (65% Argon, 35% Hydrogen), N5 at 99.98% purity.
Air: Should be clean, dry, and oil-free.
Methane: 93% pure.
Typically used plasma gases include Compressed Air, Oxygen, Nitrogen, and Argon-Hydrogen. Shielding gases help in arc constriction and cooling, enhancing the cut quality by reducing oxidation at the cut edge. The choice of gases depends on the material you’re cutting and the desired cut quality. Always refer to the manufacturer’s instructions for the best results.
3. Arc Voltage: The Balancing Act
Arc voltage is crucial for controlling the torch height and, consequently, the quality of your cut. Higher arc voltage means a taller torch height, which affects the bevel angle and overall cut quality.
Keep an eye on the cutting speed—it directly influences arc voltage. As speed increases, voltage drops, and vice versa. This relationship is vital for maintaining quality cuts, especially around corners and intricate contours.
Relation between the arc voltage and cutting speed. (Note: Graph is dependent on system and metal thickness)
THC (torch height control) reacts like this: The torch will lower as speed decreases, or rise as speed increases. THC must be turned off or “AVC Disabled” when speed decreases.
4. Torch Height: The Perfect Distance
Getting the torch height right is key, especially during piercing and cutting.
Piercing Height: Set at 1.5-2 times the ideal stand-off distance.
Cutting Height: Maintained during the cut for optimal results.
How does it work? The torch height control system (THC) adjusts the torch based on the surface, ensuring consistent cut quality. Remember, the THC is “blind” before cutting starts, so it must first touch the material to detect the initial position.
5. Cutting Speed: The Sweet Spot
Speed is everything when it comes to plasma cutting. The correct cutting speed minimizes dross and ensures a clean cut. Follow the cutting charts provided by your equipment manufacturer to find the optimal settings for amperage, arc voltage, and torch-to-work distance. Proper handling and storage of consumables is also crucial to prevent damage and contamination.
Example of plasma arc formation From left to right: Low cutting speed, Correct cutting speed, Fast cutting speed
6. Kerf Width: Precision Matters
Kerf width, the void created by the cutting process, is crucial for the dimensional accuracy of your parts. A wider kerf is often the result of slower speeds or higher power settings. Typically, kerf width is about 1.5-2.0 times the nozzle’s orifice diameter. Regular torch maintenance and proper mounting on the gantry arm ensure accurate kerf width control.
7. Coolant Condition
Regularly replace the coolant (every 6 months or quarterly for heavy use) and completely flush the system to prevent performance issues and torch failure.
By considering these critical factors, you’ll be well on your way to achieving top-notch plasma cutting quality and optimizing your workflow. Remember, attention to detail is key to producing precise, high-quality cuts.
Text: Thermacut® Photo: Archive of Thermacut, k.s.
In today’s manufacturing landscape, efficiency and cost-effectiveness are paramount. One choice that manufacturers and business owners face is either to choose high priced OEM consumables, or to source their parts elsewhere. This blog explores the cost-saving benefits and vital role that aftermarket consumables play in precision cutting.
Cost-Effective Solutions
Aftermarket consumables offer a lower-cost alternative to OEM parts, without compromising on quality.
Here are some benefits:
● Lower Initial Investment: Aftermarket consumables provide similar quality at a lower cost, helping businesses better preserve their budgets.
● Extended Lifespan: Replacement parts suitable for OEM machines ensure reliable performance and a reduction in maintenance costs.
● Customized Solutions: Aftermarket suppliers offer personalized support and customization, optimizing cost-efficiency for the specific needs of your systems, regardless of the brand.
● The Role of Aftermarket Consumables in Precision Cutting Applications
● Precision cutting requires accuracy, consistency, and reliability. Aftermarket consumables enhance cutting systems in several ways:
– Consistent Cut Quality: Engineered for precision, they ensure uniform cuts, meeting stringent tolerances.
– Enhanced Productivity: They reduce the need for manual adjustments and downtime, increasing efficiency and lowering production costs.
– Cost-Effective Maintenance: Offering an alternative to OEM parts, they help maintain cutting systems without high costs.
Thermacut® Aftermarket Consumables: Your Reliable Partner
Thermacut® provides premium replacement parts for plasma, laser, and oxy-fuel cutting systems. They offer a wide range of consumables compatible with major OEM brands like Hypertherm®, ESAB®, and Kjellberg®.
Replacement Parts
Thermacut® offers exceptional replacement parts to keep systems running smoothly without the need for new machines. Fill out the contact form below to find and quickly receive the parts you need. In conclusion, aftermarket consumables like those from Thermacut® provide significant value by enhancing performance and saving costs, making them essential for achieving manufacturing excellence.
Unlock superior cutting performance with Thermacut’s premium consumables. For more information, contact sales@thermacut.com today!
Text: Thermacut, k. s., Photo: archive of Thermacut, k. s.
Are you in the world of metal fabrication? Choosing the right power supply can make a significant impact on the quality of your work. The decision to purchase a plasma cutter is about more than the type of work you intend to perform. Several factors make plasma cutters a good choice for busy manufacturers, DIY, artists, and small workshop cutters who wish to upgrade fabrication processes by adding precision, speed, and capability.
This guide provides insights into some crucial questions to consider before selecting a plasma cutting system tailored to your requirements.
Table of Contents:
What material can be cut with a plasma cutter?
How much is a portable plasma cutter?
Why is the duty cycle important?
Are plasma cutters portable?
What power is needed?
What PPE to wear for plasma cutting?
1. Ideal Materials for Plasma Cutting
Steel and aluminum alloys are considered ideal for plasma cutting. Both contain highly conductive properties. Electricity and heat can flow through Brass and copper similarly, due to how heat dissipates over these materials, specialized techniques and consumables can be employed to cut similarly to titanium, and anything with thermal conductivity or resistances drastically different from steel and aluminum alloys.
2. Cost Considerations: Plasma Cutter Pricing
Portable plasma cutting machines priced under $500 are often designed to be smaller and more compact, making them convenient for lighter cutting tasks or simpler projects. However, machines that boast higher amperage levels, durable duty cycles, precise cutting technology, compatibility with CNC systems, and a reputable brand can command prices as high as $20,000. Typically, machines that offer this comprehensive set of features tend to average between $3,000 and $5,000 in cost. These mid-range machines strike a balance between performance, advanced capabilities, and affordability for various cutting needs.
3. Understanding the Significance of Duty Cycle
Duty cycle indicates the proportion of time a machine can run without overheating within a set duration. For instance, in a 10-minute cycle, a 60 percent duty cycle allows the machine to run smoothly for 6 minutes, which is 60% of the total time. Factors such as output power and material thickness impact this operational duration. Machines with a duty cycle below 100% need intermittent breaks within 10 minutes, essential for plasma cutters and other electrical tools to prevent overheating.
4. Assessing the Portability of Plasma Cutters
Plasma cutters vary in portability depending on size, weight, and design features. Smaller, more compact models are easier to maneuver. Larger and heavier plasma cutters, while powerful, are typically less convenient to move around and are better suited for stationary or more industrial applications where mobility isn’t a primary concern. Some plasma cutters include features like handles or wheels to enhance portability, making them easier to transport from one location to another. Overall, the portability of a plasma cutter depends on its size, weight, and specific design features.
5. Required Power Specifications for Plasma Cutters
Plasma cutters have specific power requirements including voltage, amperage, and phase ratings for your outlets. Smaller models commonly use 120 or 240 volts on a single-phase power system, while larger models operate on 3 phase power and may require a breaker rated for 40 amps. Some plasma cutting systems can automatically adapt to different voltages. Reviewing the plasma cutter specifications and documentation to find voltage and amperage. Regular circuit breakers are typically rated for 15 or 20 amps, insufficient for a plasma cutter. Upgrading the circuit or installing a heavy-duty breaker connected to the outlet with a higher amp rating can address this. The latter allows a dedicated circuit for the cutter while enabling other workshop outlets for general use, though it involves additional expense for the new outlet.
6. Essential Personal Protective Equipment (PPE) for Plasma Cutting
Eye and face protection
Eye and face protection is vital during plasma cutting to shield your eyes from intense light (UV rays), debris, and sparks. While safety glasses are the minimum recommendation, using a welding helmet or face shield offers superior protection. Choosing the right shade level for the welding helmet according to the plasma cutting current ensures optimal eye protection.
Clothing made from flame-resistant materials is essential for plasma cutting safety. Wearing long-sleeved, fire-resistant jackets, and pants provides effective protection against sparks and burns.
Plasma Cutting Current
Welding Hood Shade Level
40 to 60
6
60 to 80
8
80 to 300
8-10
Lens shade selector for plasma cutting – AWS F2.2:2001 R2019
Hand protection
Hand protection is critical; opt for heavy-duty, heat-resistant gloves to shield your hands from burns and sparks. Gloves that balance heat resistance with dexterity aid in maneuverability and protection.
Respiratory protection
is necessary, especially in confined or indoor spaces during plasma cutting. Use a respirator and ensure proper ventilation to prevent inhaling hazardous fumes or gases, safeguarding your respiratory system from potential harm.
Ear protection
Ear protection is paramount in environments with excessive noise levels, such as when using a downdraft table during plasma cutting. Utilize properly fitted earplugs, earmuffs, or a combination of both to protect your hearing, especially when sound levels exceed 100 decibels.
Source
Level
Gas Lawn Mower
80-85dB
Plasma Cutting
100dB+
Rock Concert
110dB+
Common sources of noise levels – CDC.gov
Text: Thermacut® Photo: Archive of Thermacut, k.s.
Plasma cutting machines are becoming increasingly used in a wide array of applications. Any Investment in new cutting equipment is a significant decision where major breakdowns or minor performance decreases can affect overall productivity.
Budgeting, assessment of market offerings, and consideration of return on investment are all important factors to ultimately make a well informed decision in purchasing any product and particularly when choosing the right plasma cutting machine.
Proper maintenance and regularly checking vital components ensure equipment maintains excellent condition. Regular service, upkeep, and adhering to manufacturer recommendations all support the optimal performance levels and promote high quality results.
In this brief guide we’ll highlight some maintenance ideas and intervals that can help to ensure components in your plasma cutter keep operating smoothly.
Why is maintenance important?
Maintenance for plasma cutting machines is crucial, falling into three key categories: safety, ROI, and performance. Safety is paramount, ensuring industrial machinery operates without risks. Regular maintenance extends machine lifespan, improving ROI, and maintains top-notch cutting quality and efficiency.
Before each use
1. Inspect the torch body and handle. If the torch body is cracked, it will collect more debris affecting safety. Any damaged components should be repaired or replaced to prevent gas leaks and ensure safe operation of the plasma cutter.
2. Check the power cable and leads for any cuts, fraying, or exposed wires. Repair or replace if damage is found. Any twists or high-strain points in the wire should be further inspected for damage that could affect performance of the plasma cutting system.
3. Ensure the correct installation of consumables. Check the orifice is round and free of any debris lodged between the shield and nozzle. Apply a thin coat of dielectric to the torch O-ring if it is dry. If the O-ring is missing or damaged, replace it with a new lubricated o-ring.
4. Connect the system to the input power supply, release pressure on the gas regulator, connect the air line, switch the system to the “ON” state. After the automatic diagnostic check, inspect and if needed, adjust the air pressure to the desired value. Once all checks and necessary adjustments are made, proceed with usage.
Daily checklist
1. Inspect the torch body for cracks or exposed wires. Check handheld torch safety trigger for debris and test proper operation.
2. Remove power and Inspect cap sensor safety switch behind consumables. Ensure free of debris.
3. Check all cables for strain relief and power cords for wear, and exposed wires. Correct issues and replace cables or wires if needed.
4. Check connector hoses, and connections. Ensure fittings are secure and free of damage. Replace if necessary.
5. Check the work lead clamp and ensure tight fit to avoid arcing and contamination.
6. Check torch consumables for wear.
7. If your machine has any sensors, ensure proper operation.
Weekly Maintenance
1. Ensure proper operation of safety switch to prevent accidental firing during use of handheld or mechanized torches.
2. Clean machine with degreaser and a rag to remove any excess metal, dirt, and grease.
Monthly Maintenance
1. Maintain primary air filter and any accessory air filters.
2. Inspect fiilter for dirt and o-ring for wear, cracks and pinches.
3. Verify clean, dry, air free of oil or contaminates from air compressor to plasma cutter, purge excess moisture buildup.
Every 3 Months
1. Check the cutting torch exposed wire or cracks in the torch body.
2. Check the gas hose, filter elements and connections for leaks.
3. Check with your manufacturer to determine if any new maintenance is recommended, cleaning with compressed air can keep your machine at peak performance.
Annual Maintenance
1. Have a professional safety inspection performed by a trained technician if removing the cover.
2. Examine maintenance logs and assess future maintenance requirements.
If any damage is found during an inspection, always identify and assess any damage to the input power lead/plug, torch, torch lead, airline hose, connectors, or filter components. When necessary, repair or replace the damaged components accordingly. Do not operate the system unless it fully complies with safety standards. Always take necessary precautions to avoid exposure to dust and contaminants. Prioritize your safety, the safety of your colleagues, and the environment. Wear the appropriate Personal Protective Equipment (PPE) as required by your organization and local laws.
Text: Thermacut® Photo: Archive of Thermacut, k.s.
