Stahlwille series 50 bi hexagon sockets have 12in square drives and come in metric sizes they are made from hpq high performance quality steel and are chrome plated stahlwille hpq sockets are manufactured from selected tough steel alloys this results in extremely high load capacity with exceptionally thin rings and walls the sockets are free from cadmium and therefore suitable for use on titanium alloys and titanium fasteners such as those used in the aerospace industry where safety is crucial