A wrench is a common tool used to remove and install threaded couplings (bolts, nuts), and it is also one of the most popular products in the mro mall. Due to the differences in the specific structure, location and force strength of the threaded connection, there are many types of wrenches. Here are types of several commonly used wrenches and their functions, let us take a look.

01
Wrenches

The inner holes at both ends of the Torx wrench are regular hexagons. According to its closed size, it is divided into 8-10mm, 12-14mm, 17-19mm and so on.
When using, the Torx wrench with the corresponding closed size should be selected according to the size of the bolt or nut. Compared with the open-end wrench, because the torx wrench can be turned and re-sleeved after being turned 30 degrees, it is suitable for use in narrow occasions, and has high strength, so it is not easy to slip off during use.

02
dual-purpose wrench
One end of the dual-purpose wrench is an open-end wrench, and the other end is a Torx wrench. It is mainly used for tightening and dismantling nuts and bolts of general standard specifications. The opening direction of the dual-purpose wrench is staggered by an angle from the handle, usually 15 degrees, 45 degrees, 90 degrees, etc., which is convenient for pulling in restricted parts. Its specifications are expressed by the width (mm) of the opening at both ends. Dual-purpose wrenches are usually forged with 45 steel and 50 steel and heat treated. Some foreign dual-purpose wrenches use inch units, which are suitable for removing inch bolts.
When using, a dual-purpose wrench with the corresponding opening size should be selected according to the size of the bolt or nut. To prevent wrench damage or slippage, pull should be applied to the thicker side of the opening.

03
socket wrench
The socket wrench is a convenient, flexible and safe tool for removing bolts, and it is not easy to damage the edges and corners of nuts during use. The sleeve is in the shape of a short tube, one end is dodecagonal or hexagonal, which can cover the bolt head; the other end has a square head hole, which can be matched with the square tenon of the matching handle. Common socket wrenches are 6.3mm series, 10mm series and 12.5mm series. In addition to the common standard sockets, there are many special sockets, such as: hexagonal long sockets, hexagonal or dodecagonal flower sockets, pneumatic sockets, screw sockets, etc.

04
adjustable wrench

Adjustable wrench, also known as adjustable wrench, can arbitrarily adjust the opening size within a certain range, and is suitable for irregular bolts or nuts. Its specifications are expressed by the width of the large opening x the length of the wrench (mm).
In use, the jaws should be adjusted to the same width as the opposite side of the bolt or nut, and tightened so that the wrench can move the jaws to withstand the thrust, and fix the jaws to withstand the tension.
The disadvantage of the adjustable wrench is that the operation is inconvenient, the worm needs to be rotated to open or narrow the movable jaw, and the wrench is easy to slide off the bolt.

06
torque wrench
Torque wrenches are mainly used for assembling bolts and nuts with specified torque values. For example: cylinder head, connecting rod, crankshaft main bearing and other bolts. Commonly used torque wrenches are preset force type and pointer type.

08
Allen key
The hexagon wrench is an L-shaped hexagonal bar-shaped wrench, which is specially used for screwing hexagon socket screws. Suitable for tightening or removing round nuts on machine tools, vehicles and machinery.