This device, despite its complex structure, is considered an accessory of the pipe bending machine and is used in systems where pipes of various wall thicknesses are employed. A common issue with thin-walled pipes is wrinkling during the bending process. The mandrel device is placed inside the pipe and prevents flattening and wrinkling during bending operations. The device is manufactured in two types: hydraulic and pneumatic. The hydraulic type uses oil with a viscosity of 68H as its driving force. Two hydraulic control valves, along with the main control valves, receive oil from the hydraulic oil reservoir of the pipe bending machine. The pneumatic version uses compressed air supplied by a compressor that is installed on the device based on customer requirements. The Industrial Group “Khat Ran” specializes in professional maintenance and resizing of mandrel devices.