The fundamental difference between the two processes lies in the physical state of the nitrogen donor. During plasma nitriding, nitrogen capable of diffusion is supplied from the plasma to the surface; in gas nitriding, this is from ammonia gas.

Plasma nitriding offers the following advantages over gas nitriding:

• No harmful ingredients like ammonia are used; only non-toxic gases contained in the air.
• No toxic waste gas is generated; nothing has to be subsequently combusted.
• Gas consumption is substantially lower than gas nitriding.
• Operating a plasma nitriding plant does not require a permit.
• There is the option of partially treating components.
• Stainless steels can be nitrided without chemical activation.
• Sintered materials can be treated with extremely tough dimensional requirements.