Why is argon commonly used in plasma arc cutting?

Argon is commonly used in plasma arc cutting primarily because of its unique properties that enhance the stability of the plasma arc. When argon is introduced into the cutting process, it acts as an inert shielding gas that helps to stabilize the arc and maintain its integrity. This stability is crucial for achieving a consistent cut quality and depth, as fluctuations in arc stability can lead to variations in heat input and material removal rates.

Additionally, argon has a relatively high atomic mass, which contributes to better thermal conductivity and energy transfer. This allows for a more efficient heating of the workpiece, resulting in cleaner cuts. While other gases like nitrogen and oxygen may be used with specific materials or for different applications, argon's inert characteristics make it ideal for maintaining the required environment for optimal arc performance without reacting with the material being cut.

The other options, while they reflect some relevant aspects about gases, do not address the specific advantages of argon in the context of plasma cutting as effectively as its unique properties for arc stability do.