Spanner wrench can be divided into: ends with a corner with a hexagonal or twelve-hole side of the work, for work space is small, can not use ordinary wrench occasions. Wrench: one end with the same single-head wrench, wrench the same with the other end, both ends of the screw turn the same size bolt or nut. Wrench: opening width can be adjusted within a certain size range can be wrenching bolts or nuts of different specifications. Hook wrench: also known as crescent wrench for wrenching the thickness of the restricted flat nut and so on. Socket wrench: it is more angular with a hexagonal or twelve holes of the sleeve and is equipped with handle, extension bar and other annexes, especially for small twist or turn position is very very deep depression, bolts or nuts . Hexagonal wrench: into the L-shaped hexagonal rod wrench, dedicated wrenching hex screws. Torque wrench: it is wrenching bolts or nuts, can display the applied torque; or when applied torque reaches the specified value, it will give off light or sound signals. Torque wrench applies torque has clearly defined the size of the assembly work.