ISO 2936:2014 specifies the dimensions, the method of test, the designation, and the marking of hexagon socket screw keys. It also specifies the minimum values of Rockwell hardness that are to be met.
Its specifications apply for tightening of hexagon socket screws for property class less than or equal to 12,9 as defined in ISO 898-1 and for tightening of socket set screws as defined in ISO 898-5.