Patent for an improved, simple, inexpensive, durable, and efficient mandrel attachment that can be easily attached, detached, and adjusted. It has "a bar at one end with a plate for its attachment and at the other end with a cam and eccentric for detachable connection and adjustment the support carrying the cam and eccentric being hinged so as to drop down so that cylinder work can be slipped over the mandrel and then the eccentric and cam raised up and tightened to the bar to hold the work to be performed" (lines 18-27).