This blacked steel two-piece collar fits all ultrasonic presses using a 3.5″ (89mm) diameter column, which includes most USA brand ultrasonic machines and many other makes.
The are a couple of reasons to use a collar like this. One is when using a long column on a bench top machine. The problem here is that the spring that negates most of the head weight is designed for the movement range of the standard column but not for the movement range if a long column is employed. Applying the collar to the column below the moveable head will prevent running the head down so low that the counterbalance spring can come free of its hub, possibly resulting in injury to workers and damage to equipment and tooling. Worst case scenario would be if the spring itself were to go airborne and damage some plant infrastructure or another machine or person. If you can feel the column all the way up to the bottom of the head casting and the counterbalance spring can become fully extended by a lowered head, you need this item. Recent Dukane machines shipped with long columns have had a hole drilled in the column and a dowel pin driven into the hole to prevent running the head down so low as to cause a problem, and do not require this item. If you can verify the pin is there you are protected that way.
The second reason to use a this collar is if there is a reason the head needs to be moved, such as for a tool change or another application, and then the head needs to be returned to a specific spot on the column.
Split blackened steel collar 3.5″ (89mm) i.d. with two bolts.