These machine bits are typically  used by kitchen furniture manufacturers for recessing circular hinges.  This type without scribers are for laminate covered boards.
Specification:
D=35 mm|OL=65 mm|Shank Diameter=1/4 inch
    
    
    Specification:
D=35 mm|OL=65 mm|Shank Diameter=1/4 inch
        12 months
    
    
 
    
     
                     
                     
                     
                     
                     
                     
                     
             
             
             
            