0.8 are 30 amp unshielded tips so you wouldn’t use them for 1/2". 1.0mm/50 amp tips and 1.1mm/60 amp tips can be shielded or unshielded. If your using 1.1mm/60 amp shielded tips with a CNC shield you need to measure the torch height between the tip and work piece not the shield and work. If the distance between the shield and work piece is more then .035" the torch height is way to high.