DEFICIT AND ABRASION DETECTOR FOR DIE

PURPOSE:To detect the deficit and abrasion of a die in bolt working by providing an annular circuit made of a conductive member to the periphery of the through-hole of the die and detecting the value of a current flowing through it. CONSTITUTION:A thin wire 3 is fixed with an adhesive, etc., on the top surface of the through-hole 2 of the die 1 where a bolt is inserted along its circumferential part. A power source 4, a resistance 5, and an ammeter 6 are connected to the wire 3 in series and a specific current is fed throughout the working. Then, when the bolt is worked, a deficit and abrasion are easily caused nearby the through hole 2. If the deficit or abrasion occurs during the working, the thin wire 3 is easily broken. For the purpose, the current value of the ammeter 6 is checked every time the working is performed to easily decide whether the abrasion or deficit of the die 1 occurs or not.