Argon-helium shielding gas

You mainly use argon-helium mixtures when you need to bring more heat into the workpiece than with pure argon. The helium makes the arc hotter and more energetic, which pays off especially with thick sheets or highly heat-conductive materials like aluminum. The higher helium content gives a softer, wider weld pool and more penetration. Make sure the mixture matches the material and joint geometry – too much helium makes the arc unstable and the weld too wide, too little doesn't provide the desired heat input. For most cases, you're fine with a ready-made gas mixture; you don't need to experiment yourself.