Socket wrench it is composed of a plurality of hexagonal hole or bihexagonal hole sleeve and equipped with a handle, rod and other accessories, especially suitable for the screw position is very narrow or very deep pit of the bolt or nut. Socket wrenches are mainly used in 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 wrenches or adjustable wrenches and box wrenches, with socket wrenches, in addition is the bolt space restrictions, can only use socket wrenches
