For the nut end or bolt end is completely lower than the connecting surface, and the diameter of the concave hole can not be used for open spanner or adjustable spanner and plum spanner, the socket spanner is used, and the space of the bolt is limited, only the socket spanner can be used
The socket wrench is generally called the socket: it is composed of a plurality of hexagonal holes or twelve Angle holes of the socket and is equipped with a handle, a rod and other accessories, especially suitable for turning the status of a very narrow or sunken very deep bolt or nut. The sleeve is divided into metric system and British system. Although the inner concave shape of the sleeve is the same, the outer diameter and length are designed for the shape and size of the corresponding equipment. There are no unified regulations in the country, so the design of the sleeve is relatively flexible and meets the needs of the public. The socket wrench is generally attached with a set of various specifications of the socket head and swing handle, connecting rod, universal joint, rotary joint, elbow handle and so on to set into the hexagonal nut. The socket head of a socket wrench is a concave hexagonal cylinder; The spanner is usually made of carbon structural steel or alloy structural steel. The spanner head has specified hardness, and the middle and handle part is elastic.
