This TECH TIPS is provided by the experts at ESAB University.
Choosing the right cutting tip for the job is critical to performance and safety. When it comes to plasma cutting, there are two styles to consider: drag and standoff. Here’s what to know to help you make the best purchasing decision.
Drag Cutting Tips
A drag tip lets you place the tip directly on the workpiece for cutting metal ¼ inch or thinner. It produces a precise, narrow kerf, or cut width.
Drag cutting also helps if you have a shaky hand or want to follow a template. With a drag tip, choose a shield cup that will allow the torch tip to have direct contact to the cutting surface.
Some drag tips let you cut at up to 60 amps, but others are limited to 40 amps. When using a 40-amp tip, turn down the amperage on the machine’s controls.
Standoff Cutting Tips
Holding the torch about 1/8 to 3/8 inches off the workpiece increases voltage and overall cutting power. As a result, standoff cutting is preferred if you’re cutting metal thicker than ¼ inch and at current levels above 60 amps.
For this type of cutting, pair a standoff cutting tip with a shield cap that exposes the tip. This provides maximum visibility and accessibility to the cutting path.
If you can’t hold a steady standoff, switch to a shield cap with a drag shield cup. These consumables ensure proper standoff distance, while resting the torch on the work piece. The alternative is to use a standoff guide that slips over the shield cap.
In addition to a drag shield cap, some cups may have an option for a shield cap deflector, which helps protect the cup.
Tip Change?
One of the more common causes of poor cutting performance is forgetting to change the tip to match the application. For instance, a low-amp tip has a smaller orifice to maintain a narrow plasma stream at lower settings for use on thinner material. A 20-amp tip therefore can’t handle the shielding air and plasma gas flow requirements for cutting thick sections. Instead, consider a 120-amp tip to cut thicker sheet metal.
