When sourcing a used pipe bender, you must prioritize the Maximum Bending Capacity (OD and wall thickness) and the Bending Radius (CLR). Ensure the machine supports the specific materials you use, such as stainless steel, carbon steel, or aluminum. For CNC models, verify the number of axes (3-axis or 5-axis) and the control system version (e.g., Fanuc, Mitsubishi, or proprietary software) to ensure compatibility with your current CAD/CAM workflows. Additionally, check the hydraulic system pressure stability and the condition of the mandrel extractor.