EXTREMELY RARE EXAMPLE OF  COMPLETE COLLER CUD DUE TO COMPLETE COLLER BREAK WITH COMBINATION OF REEDED & PLAIN EDGE.

DEFINITION: HERE AN ENTIRE SEGMENT OF THE COLLAR’S WORKING FACE (OR HARDENED LINING) BREAKS AWAY, LEAVING A VOID THAT BEGINS AND ENDS QUITE ABRUPTLY. A KEY DIAGNOSTIC FOR A FULL COLLAR BREAK IS A “STEP-UP” AT BOTH ENDPOINTS. THE STEP MARKS THE TRANSITION FROM THE NORMAL PORTION OF THE EDGE THAT SHOWS COLLAR CONTACT TO THE AREA WHERE COIN METAL WAS FREE TO EXPAND.