Manufactured to surpass the performance test BS2558: 1954. The sockets locate directly onto the handle relieving stress on the rivet. All sockets are plated, hardened and stress relieved to ensure they retain their shape. | | Single Ended Swing Over Spanners | Single ended swingover handle spanners. Available in 7/16″ or 1/2″ Whitworth socket end size for use on fixings.