This part of IEC 61076 describes circular connectors M8 screw-locking or with nominal 8 mm snap-locking, for connection of automation devices with signal and power up to 50 V AC / 60 V DC rated voltage and up to 4 A rated current. These connectors consist of fixed and free connectors either rewirable or non-rewirable. Male connectors have round contacts " 0,48 mm, " 0,6 mm, " 0,7 mm and " 1,0 mm according to the number of ways and coding, all contacts with the same size. The different codings prevent the mating of differently coded male and female connectors. NOTE 1 M8 is the dimension of the thread of the screw locking mechanism of these circular connectors. NOTE 2 These connectors are typically used for connecting industrial automation devices for process measurement and control.