Stahlwille Series 45A AF Imperial Bi-Hexagon Sockets have 3/8in square drives. They are made from HPQ® high performance quality steel and chrome plated. The sockets have extremely high load capacity with exceptionally thin rings and walls. They are free from cadmium and therefore suitable use on titanium alloy parts and titanium fasteners, such as those used in the aerospace industry, where safety is crucial. The sockets are equipped with anti-slip drives to permit high transmission of forces to the lands of the nuts and bolts without damaging them. Manufactured to ASME B 107.1, Fed. Spec. GGG-W-641, SAE AS 954-E (test loads). MADE IN GERMANY.Stahlwille Bi-Hexagon Socket 3/8in Drive. Size: 5/16 AF.Overall length: 25mm.