Our Sites

The Cutting Top 20

Manual plasma cutting, gouging tips to make you better

These top 20 cutting and gouging tips will help get you on your way to cutting efficiently and with good quality. Photos courtesy of ESAB Welding & Cutting Products.

It’s no secret that manual plasma cutting is a relatively simple process that is easy to use. But because of its simplicity, many fabricators tend to pick up the torch and start cutting well before they’ve thoroughly learned about the capabilities of their machine.

Before jumping straight into your cutting project, take a look at these 20 tips that will help you to improve cut quality and overall productivity and make you better at using the plasma torch.

Tip #1

Before you start cutting, check the torch, consumables, and cables for excessive wear and damage. If the electrode, start cartridge, or tip orifice shows signs of wear and tear, replace it with a new component that is sized correctly for your unit. Cutting with worn-out consumables only leads to poor cutting performance (see Figure 1).

Figure 1
Damaged or worn equipment, like the consumables shown, will lead to poor cuts.


Tip #2

Use clean, dry shop air (install a filter if necessary), and match pressure and flow requirements to those of the plasma cutter. Adjust the gas pressure on the machine according to the owner’s manual. For torch leads longer than 25 feet, add 5 pounds per square inch (PSI) for each additional 25 ft. Setting the pressure when the air is flowing through the torch will ensure that you have proper pressure and airflow while cutting.


Tip #3

For cutting thicker sections, set the output at maximum. For cutting thinner material, reducing the output produces a finer (smaller kerf width) cut and lets you reduce travel speed for better control.


Tip #4

Plasma cutters often have more than one mode. In the run or standard cutting mode, there is a brief delay in restarting the pilot arc before the next cut can be made. In the rapid auto restart

mode, the pilot arc restarts the cutting arc instantly upon contact with the workpiece. Use this mode for cutting expanded metal and gratings or in gouging or trimming operations that benefit from an uninterrupted arc. In the latch or trigger lock mode, the cutting arc stays on after you release the trigger, which reduces hand fatigue on longer cuts.

Depress the trigger again to turn the arc off.


Tip #5

Select the right tip and shield cup for the job. It will be either a drag tip, a drag tip with a shield cup, a standoff guide, or a tip requiring shielded consumables. Drag cutting, in which the torch tip rests on the workpiece, works at 60 amps or less for cutting material ¼ inch or thinner. Drag cutting can reduce handshake, lets you see the tip, produces the narrowest cut width (kerf), and produces the cleanest cut with the smallest heat-affected zone (HAZ). Note that all cutting above 60 amps requires a standoff.


Tip #6

Plasma cutters in the 40- and 60-amp category are extremely popular because they allow for drag cutting or cutting with a standoff and can accommodate multiple types of input power. However, to cut at the machine’s maximum output, you’ll need to hold a standoff of about 1⁄8 in. This technique can produce the recommended cut quality on material up to ½ in. thick. It also allows you to cut material up to 11⁄8 in., but with a rougher cut surface or at a slower cutting speed. Use a standoff guide or a roller guide to maintain a consistent distance. More powerful plasma cutters might require holding a longer standoff, perhaps between 1⁄8 and 3⁄8 in. (see Figure 2).

Figure 2
A standoff guide or a roller guide can help you maintain the proper distance between the torch and the material.


Tip #7

For additional control while you cut, try leaning against a sturdy table to help steady your body. Use your noncutting hand to brace your cutting hand and make a couple of practice moves to be sure that your hands can slide freely along the length of the cut. You’d be surprised how often your elbows hit an unanticipated object.


Tip #8

To start a cut at the edge of the plate, hold the torch at 90 degrees to the edge of the workpiece. Press the trigger and pause at the edge until the arc has completely cut through the workpiece.


Tip #9

To pierce, start the pierce just off the cutting line in a portion of unwanted metal. Angle the torch slightly to direct blowback particles away from the torch tip, which greatly extends tip life. Once the arc pierces the metal, return the torch to the perpendicular position and start moving.


Tip #10

When possible, pull the torch toward you rather than pushing it away from you, and use your shoulder for movement instead of your elbow. Tilt the torch back (away from the cutting direction) about 5 to 10 degrees to minimize dross (see Figure 3).

Figure 3
Pull the torch toward you using your shoulder, instead of your elbow, for movement./p>


Tip #11

To sever the metal cleanly at the end of the cut, roll the torch slightly past perpendicular as you reach the edge of the plate (see Figure 4).

Figure 4
The photo above shows the torch rolling past perpendicular.


Tip #12

When you are cutting at the correct speed, the plasma arc under the workpiece should trail the torch at a 5- to 10-degree angle (see Figure 5). But an arc that trails straight up and down indicates that your travel speed is too low, which can produce a cut that is wider than desired, as well as excess dross. An arc with a shallow trail indicates you’re moving too quickly and you won’t sever the metal cleanly.

Figure 5
Notice how the arc under the workpiece appears to trail the torch. This indicates correct travel speed.


Tip #13

The quality surface of the cut also reveals a lot about correct and incorrect travel speeds. A good-quality cut has lines that angle slightly back from the travel direction at the aforementioned 5- to 10-degree angle (see Figure 6).

Figure 6
A telltale sign of a good cut is when the cut surface has lines that mirror the aforementioned 5- to 10-degree angle.


Tip #14

For cutting straight lines, use a nonmetallic straight edge. Another piece of metal does provide a straight edge, but it can pull the arc toward it. A roller guide can prevent this (see Figure 7).

Figure 7
A roller guide or a nonmetallic straight edge can assist you with making straight-line cuts.


Tip #15

To cut a bevel, use an elevated straight edge to support the torch. In this case it is OK to use another piece of metal because the arc is directed away from the straight edge.


Tip #16

To bevel material with a more consistent angle, use the adjustable angle on a roller guide.


Tip #17

For cutting circles quickly, easily, and consistently, use a circle cutting guide, which has a magnetic clamp and an adjustable torch holder (see Figure 8).

Figure 8
Cutting circles can be easy when you use a circle cutting guide.


Tip #18

To optimize a plasma system for gouging (such as to remove a defective weld), use gouging-specific consumables and techniques. As with cutting, the set amperage will affect the depth of the gouge; less current for a shallow gouge, more current for a deeper gouge.


Tip #19

Position the torch so that the nozzle is within 1⁄16 in. of the workpiece, but do not touch it to the workpiece because it reduces consumable life. Keep in mind that some plasma systems have a fold-back circuit that reduces output (say from 200 amps to 45 amps) when the tip touches the workpiece.


Tip #20

Hold the torch at a 25- to 45-degree angle, push the plasma arc in the direction of the gouge, and make sure you’re pushing in a safe direction as the sparks can easily travel 10 or 20 ft. Maintain the 25- to 45-degree angle for a consistent depth and width.

Before using any plasma cutter, get to know your machine by reading the owner’s manual start to finish. The manual provides detailed information about machine setup, safety, operation, and more. In fact, many of the tips contained here can be found in any decent owner’s manual. Also check YouTube for visual demonstrations of plasma cutting tips.

About the Author

Michelle Chamberlain

Global Product Manager, Manual Plasma

411 S. Ebenezer Road

Florence, SC 29501

800-372-2123