Rear Toolbar Clamp for International Harvester Rear Mounted Toolbars. 

Originally fit on International Model 146 or 170 Rear Cultivators.  Or C10,  C18A, or C18B Middle Buster Attachments. 

Clamp could be repurposed for use on 3 Point,  2 Point or 1 Point Hitch Toolbars with 2-1/4" inch diamond shape.  Clamp shank hole is 1-1/2 inch in diameter.  

Top clamp bolts has rust as shown.  Clamp would need the wedge bolt.

Case IH Clamp part numbers PO2230-C,  PO2230C,  PO19926.