To form a terminal easily complying with standards without requiring the work of shaving burrs off after caulked.

In this caulking dice 1 to caulk a terminal 6 with a circular cross section to be inserted with a wire 7 so as to form a hexagonal cross section, insertion notches 4 having a shape of one half of the diagonal cross section are formed from the butt surfaces 3 in a pair of dice bodies 2, 2 to be mutually butted, a pair of burr preventive surfaces 5, 5 to press the terminal in the insertion notches are formed in a taper shape between a pair of terminal caulking surfaces and their butt surfaces to caulk the terminal in the insertion notches, in at least one of dice bodies 2, and the terminal after caulked has a thin thickness part by the burr preventive surface 5a. The pair of burr preventive surfaces 5 have a steeper grade than that of the terminal caulking surfaces, and a distance between the but surface butted by the bur preventive surfaces 5 and the terminal after caulked is set within a range of standards.