Brief Introduction on Pipe Hole Punching Machine SLS Pipe Hole Punching and Flanging Machine is specially designed for punching collar holes on metal tubes as MS,SS,Copper and Aluminum which widely used in air conditioner,refrigerator,heat exchanger,Oil Tubes,Medical Water Separating System,Water Solutions…Etc Machine adopts "extruder system", forming …Dimple hole punching or piercing and Mandrel hole punching. DIMPLE STYLE HOLE PUNCHING - The most cost-effective way to punch or pierce a hole in a round, square, or rectangular tube. There are two styles of dimple punching. Single-dimple and double-dimple. The double dimple version uses two individual punches that travel towards each other ...Automatic CNC Pipe Tube Punching Machine . Hydraulic CNC Tube Punching Machine is used for punching round hole, square hole, rectangle hole, oblong hole and any shape hole in any shape tube ,such as round tube, square tube, rectangular tube, elliptical tube, angle steel, etc. And the metal can be steel, aluminum, copper, stainless steel, PE, etc.