Proximity Sensor - 8 mm Diameter, Shielded, Normally Closed - NPNWintrss's 8 mm diameter shielded inductive proximity sensors are extremely useful general purpose die protection sensors. This sensor has a threaded housing, and should be secured into an M8 x 1 threaded hole with thread locker. If the sensor is to be removed from the die during maintenance, epoxy it into a removable bushing or insert. This inductive proximity sensor is Normally Closed, in other words, it actuates when metal leaves the sensing field,