Locking device for snow chains

A locking device for snow chains, said snow chains comprising an inner side portion (2) that can be closed as a ring and is suitable to be placed on an inner side of a tire (3), an outer side portion (4) suitable to be placed on an outer side of the tire (3), said portions being linked by elements (5) creating friction on the road, the locking device (8) comprising a fastening block (10) connected to a first end (9) of the inner side portion, a head (65) connected to a second free end of the outer side portion and able to engage with the fastening block and an operating device (50), that can be operated by a user from the outside of the tire, acting on the fastening block to open the ring of the inner side portion, the fastening block comprising two half-shells (11), formed from a sheared sheet metal plate, assembled together and spaced apart so as to define a seat to accommodate a fastening mechanism.