What Is an Edge Start in Plasma Cutting?

What Is an Edge Start in Plasma Cutting?

An edge start is a method of initiating a plasma cut from the edge of the material instead of piercing through it. This technique takes advantage of the plasma system’s pilot arc, allowing the torch to establish a stable cut with less stress on the consumables and torch.

How an Edge Start Works
When the trigger is first pulled, the plasma torch generates a pilot arc. This is a low-amperage arc that seeks grounded material but does not yet operate at full cutting power.

While the torch is off the material or grounded to air, the pilot arc remains active.

As soon as the torch contacts the edge of the material, the arc transfers to the plate and ramps up to full cutting amperage.

Cutting begins immediately, without the violent blowback associated with piercing.

This controlled transition from pilot arc to full arc is what makes edge starting so effective.

Edge Starts and Rapid Arc Restart
When using a system with Rapid Arc Restart mode, edge starts become even more efficient.

As the torch moves:

When cutting across the material, the arc runs at full power.

If the torch passes over a gap or briefly loses contact with the material, the arc automatically drops back to the pilot arc.

Once it reaches material again, it instantly transfers back to full cutting power.

In Rapid Arc Restart mode, the operator can hold the trigger continuously, allowing seamless transitions between air gaps and material without stopping or re-triggering the torch. This is especially useful for expanded metal, slotted parts, or complex profiles.

Why Edge Starts Are Beneficial

Reduced Consumable Wear
Piercing forces molten metal upward into the nozzle and electrode. Edge starts avoid this entirely, extending consumable life.

Cleaner Cut Starts
Starting from the edge produces a smoother lead-in with less spatter and fewer arc disruptions.

Less Torch Stress
By eliminating pierce pressure and heat buildup, edge starts reduce mechanical and thermal stress on the torch.

Improved Cutting Reliability
Edge starting provides more consistent arc transfer, especially on thicker materials or reflective metals.

Best Practice
Whenever part layout allows, edge start instead of piercing and use Rapid Arc Restart mode to maintain arc continuity across gaps. It’s a simple technique that improves cut quality, reliability, and operating costs.