Capri Tools high performance sockets are trusted by professionals for even the most demanding applications. size socket. Each socket is expertly coated with manganese phosphate, the preferred coating in military and aerospace, which offers superior protection and corrosion resistance compared to black oxide coating on other impact sockets.3/8 in Drive 13/16 in 6-Point SAE Shallow Impact Socket We use premium Chrome Molybdenum steel tempered with our proprietary heat treatment process to make these impact sockets.