Abstract: A quick disconnect arbor and die head for a tube stock sizing apparatus. A plurality of arbors and die heads are slidably mounted to a tube stock sizing apparatus and are respectively urged into engagement with the inwardly facing and outwardly facing surfaces of a section of tube stock. A hydraulic piston arrangement is operable to move the arbor members and die heads to and from the tube stock. An annular member surrounds the arbor members and die heads. Spring biased pins mounted in the annular member releasably engage and secure the arbor members to the annular member. An external tool is engageable with the top end of each pin to pull the pins upwardly disengaging the arbor members. A rod extends through the annular member and contacts the pin and secures the pin in the upward disengaged position. Each die head includes a leg with a recess extending freely into a hole.