Fixed wrench specifications and dimensions

The open-end wrench used for the outer hexagon corresponds more accurately to the hexagon nut, as there are hexagon head bolts and small hexagon head bolts.
Commonly used open-end wrench specifications – corresponding thread specifications
7–M4、
8–M5、
10–M6、
14–M8、
17–M10、
19–M12、
22–M14、
24–M16、
27–M18、
30–M20、
32–M22、
36–M24、
41–M27、
46–M30、
55–M36、
65–M42.
The minimum specification of the complete set of hexagonal wrenches is 3, and its corresponding relationship is S3=M4、S4=M5、S5=M6、S6=M8、S8=M10、S10=M12、S12=M14-M16、S14=M18-M20、S17=M22-M24、S19=M27-M30、S24=M36、S27-M42. The calculation method for the diameter of the threaded bottom hole before tapping; For brittle materials, the basic dimension is -1.0826 pitch, and for plastic materials, the basic dimension of the thread is – pitch+0.1
Brittle materials are in a pure cutting state during tapping, and the size of the bottom hole is the diameter of the thread root circle. Plastic materials undergo plastic deformation due to stress during tapping, and the material will move towards the smaller diameter of the thread. Therefore, the bottom hole should be appropriately enlarged. For threaded holes below M6, regardless of material properties, the basic size pitch should be uniformly used
Wrenches are classified according to their purpose, style, etc. They have fixed sized openings on one or both ends for turning a certain size of nut or bolt. Plum wrench: It has working ends with hexagonal or twelve pointed holes at both ends, suitable for situations where the working space is narrow and ordinary wrenches cannot be used.
Dual purpose wrench: One end is the same as a single headed wrench, the other end is the same as a ring wrench, and both ends are used to turn bolts or nuts of the same specifications.
Active wrench: The opening width can be adjusted within a certain size range, and can rotate bolts or nuts of different specifications. Hook wrench: also known as crescent wrench, used to turn flat nuts with limited thickness. Socket wrench: It is composed of multiple sockets with hexagonal or twelve pointed holes and equipped with various accessories such as handles and extension rods, especially suitable for turning bolts or nuts with very narrow or deeply recessed positions. Hexagonal wrench: an L-shaped hexagonal bar wrench designed for turning hexagonal screws. Torque wrench: It can display the applied torque when turning bolts or nuts, or emit a light or sound signal when the applied torque reaches the specified value. Torque wrenches are suitable for assembly work with clear specifications for torque magnitude.