Stop Burning Through Your Plasma Consumables!

When shops look for more productivity from a high-definition plasma cutting system, cutting speed usually gets most of the attention. How many inches per minute can you cut? How quickly can you move from one part to the next?

But there's another part of the cutting cycle that deserves just as much attention: the pierce.

Every time a plasma torch starts a cut in the middle of a plate, it has to pierce completely through the material before moving along the programmed cut path.

​During those few seconds, the displaced molten metal has to go somewhere, and much of it is being forced back toward the torch. That molten material can shorten your consumable life, affect cut quality, and add unnecessary time and cost in rework.

So, if it feels like your plasma consumables aren't lasting as long as they should, the consumables themselves might not be the problem. Your piercing process could be!

So why is plasma piercing so hard on consumables? Well, let's think about what happens when you pierce a piece of plate.

Your plasma arc begins heating and melting the metal, but until it penetrates all the way through, that molten material can't escape through the bottom of the plate, so it tends to travel upward, splashing toward your nozzle and other torch components. When you are cutting plate throughout a shift, that exposure is repeated every time the torch starts another pierce.

That's why pierce height matters.

Some modern plasma power sources have the ability to transfer your arc from much higher, and starting farther away from the plate gives that molten metal more room to disperse instead of sending as much of it toward the consumables. Once the arc has completely penetrated the plate, your torch can descend from its pierce height to a normal cutting height and start moving along your cut path.

The process happens quickly, but getting that sequence right can have a real impact on your consumable life. 

Six Ways to Reduce the Stress of Piercing

Chain cutting

Chain cutting keeps the torch on as it cuts through the scrap metal between one nested part and the next. Instead of stopping and piercing the plate again for each part, it cuts through the material connecting them. Fewer arc starts mean fewer pierces and less consumable wear.​

However, it works best for simple parts because holes, slots, and other internal features still require separate pierces.
Part geometry and nesting software may also limit where this technique can be used. When planning a group of parts, look for opportunities to reduce unnecessary pierces where feasible. 

Edge Starting

Starting at the edge of the plate can help protect your consumables. Because the torch isn't piercing through the middle of the material, molten metal is directed away from the torch rather than forced back toward it.

Edge starting can be challenging on an automated  table because the plate edge may not be in exactly the same position each time. The operator or system must position the torch accurately. For this reason, edge starting is most practical when cutting material near the system’s thickness limit OR when the setup can be performed consistently. 

Pre-Piercing

Instead of asking the plasma torch to pierce every starting point, holes are created in the plate before plasma cutting begins.

The torch can then start its cut at the pilot holes you made, essentially giving it an internal "edge start".
​
This approach can reduce the stress associated with piercing thick material, but positioning becomes critical.

The plasma torch needs to locate the pre-pierced hole accurately enough to establish the arc where intended.

So, while pre-piercing can solve one problem, it introduces another consideration: repeatable positioning.

Double Piercing

If you're cutting thick plate and edge starting doesn't make practical sense for the application, then you might want to try a double pierce. 

It's kinda in the name, but we'll explain it anyway.
What you'll want to do is pierce only partway through the material, then remove the created slag, and run your second pierce all the way through.

​That first partial pierce creates an area that can help redirect molten metal away from the torch while the second pierce is running.

This technique also requires accurate torch positioning and an operator or system capable of repeating the process reliably.

Moving pierce

Now this technique requires some finesse. ​Instead of just keeping the torch stationary while it penetrates the plate, your torch is going to begin moving right after the arc transfers.

Because the torch is moving, molten metal can trail behind it rather than splashing directly upward toward the torch body. The arc will penetrate progressively as the torch travels. 

Travel speed is important here, because the torch has to travel far enough to complete the pierce without transitioning into the normal cutting process too soon. You also have to leave enough room in your nest layouts to account for that lead up.

In other words, moving piercing can provide benefits, but those benefits depend heavily on operator skill, programming, and (again) consistency.

advanced piercing technology

Hypertherm has developed several technologies to help protect consumables and increase piercing capacity on certain plasma systems. 
​
Argon-assisted piercing sustains the arc over a greater distance, allowing it to transfer from a higher pierce height and reducing molten-metal damage.
​
PowerPierce uses liquid-cooled shielding to prevent molten metal from sticking to the nozzle. It can be used alone or with argon-assisted piercing to extend consumable life and reduce the need for edge starts.
​
Depending on the Hypertherm system and application, PowerPierce may be used alone or with argon-assisted technology. Together, these features can increase piercing capacity and, in some applications, reduce the need for edge starts.

HyPilot Cartridge

The HyPilot cartridge is purpose-built for industries such as structural steel, pipe and tube, pressure vessel, and automotive manufacturing, which often require applications with high pilot arc time to optimize productivity and avoid downtime, making consumable longevity a critical factor in overall system performance.

Designed specifically for robotic and cobot plasma cutting environments, the HyPilot cartridge addresses the unique demands of 3D applications such as cast trimming, where prolonged pilot arcing and higher stand-off heights accelerate consumable wear. When incorporating advanced, patent-pending NickelPlus® technology for continuous pilot arcing applications, the cartridge delivers at least twice the life of standard 105-amp mechanized cartridges, reducing operating costs without sacrificing productivity or cut quality.
​
As manufacturers increasingly adopt robotic plasma cutting because of its flexibility and speed compared to traditional methods, the HyPilot cartridge builds on that value by lowering the total cost of ownership.

A plasma consumable is like any consumable, eventually it has to be replaced. That's just part of the process. How quickly it needs to be replaced is another story.

Piercing puts some of the greatest stress on a plasma torch during the entire cutting cycle. The right pierce height, timing, cutting strategy, and equipment can help control that and keep your consumables productive for longer.
​
But it's only one part of the equation. Saving a few seconds on cutting time doesn't mean much if you're only going to lose that productivity to premature consumable changes, excessive grinding, recuts, or machine downtime. An impressive cut speed doesn't mean much if the process can't produce acceptable parts consistently throughout a shift.

A good plasma process needs to balance cutting speed, piercing time, consumable life, cut quality, part repeatability, operator involvement, and overall cycle time.

If you're replacing plasma consumables more frequently than expected, struggling with thick-plate piercing, or trying to improve your plasma cutting productivity, Earlbeck can help you take a closer look at the complete process.

Talk with our team about your plasma application, equipment, and consumables, and we'll help you find ways to get more productivity from every cut!