The wrench is a commonly used installation and removal tool. Hand tools that use the principle of leverage to turn bolts, screws, nuts, and other threads to hold the openings or sockets of bolts or nuts. The wrench usually has a shank portion at one or both ends of the shank to apply external force, and the shank portion can apply external force to turn the bolt or nut holding the opening or sleeve hole of the bolt or nut. When using external force on the shank along the direction of thread rotation, you can turn the bolt or nut.
Wrenches are usually made of carbon structural steel or alloy structural steel.
1. Chromium vanadium steel: The chemical symbol CR-V is the better quality among steels;
2. Carbon steel: average quality, more circulating in the market
Second, classification uses
There are basically two types of wrenches, dead wrenches and adjustable wrenches.
The former refers to a wrench that has a fixed number written on it, and the latter is an adjustable wrench.
1. Wrench: A fixed-size opening is made at one or both ends for turning a nut or bolt of a certain size.
2. Torx wrench: It has a working end with a hexagonal hole or a twelve corner hole at both ends, which is suitable for situations where the working space is narrow and ordinary wrenches cannot be used.
3. Dual-purpose wrench: One end is the same as a single-headed spanner, and the other end is the same as a Torx wrench, and the two ends are turned with the same specifications of bolts or nuts.
4. Adjustable wrench: The width of the opening can be adjusted within a certain size range, and can be used to turn different specifications of bolts or nuts. The structure of the wrench is that the fixed jaw is made of a flat jaw with fine teeth; one end of the movable jaw is made of a flat jaw; the other end is made of a concave jaw with fine teeth; press the worm down to move The jaw can be quickly removed and the jaw position can be changed.
5. Hook wrench: Also known as crescent wrench, used to turn flat nuts with restricted thickness.
6. Socket wrench: It is composed of multiple sockets with hexagonal holes or twelve corner holes, and is equipped with a variety of accessories such as handles and posts. It is especially suitable for turning bolts with very narrow positions or deep recesses. Or nuts.
7. Hexagonal wrench: L-shaped hexagonal rod wrench, special for turning hexagonal screws. The model of the Allen wrench is based on the hexagonal opposite side dimensions, and the size of the bolt has national standards. Uses: It is specially used for tightening or removing round nuts on machine tools, vehicles, and mechanical equipment.
8. Torque wrench: it can display the applied torque when turning the bolt or nut; or when the applied torque reaches the specified value, it will emit a light or sound signal. Torque wrenches are suitable for applications where the torque is clearly specified.
Third, manual wrench.
Manual wrench, also called ordinary wrench, is mainly used in ordinary life and work. It is relatively simple to use. It is mainly divided into single-head wrench, double-head wrench, adjustable wrench, plum wrench, multi-purpose wrench, percussion wrench, and socket wrench , Socket driver, torque wrench, torque wrench, cross wrench, ratchet wrench, hook wrench, hex wrench, inner square wrench, manual clutch torque wrench, pipe wrench, T-wrench, L-wrench, trident wrench, crescent moon Wrenches, drum wrenches, tire wrenches, spark plug wrenches, filter wrenches, combination wrenches, other wrenches, etc. The torque wrench is divided into a sounding wrench, a pointer wrench, and a digital display wrench.
Use of manual wrench
1. Select the appropriate wrench according to the characteristics of the fastened fastener.
2. Tighten, hold the end of the wrench handle with your hand, and tighten firmly clockwise; loosen, and turn counterclockwise.
Features of manual wrench: simple operation, low price and high labor intensity.
Fourth, open-end wrenches
Screws are the main fasteners in mechanical equipment. Opening wrenches are important tools for machining, production, and maintenance in the mechanical industry. This project is a revolution in traditional wrench tools. It has the following advantages.
1. It can work fast, working three to four times faster than a traditional wrench, and faster than a fast wrench.
2. One open-ended wrench can be used for 2-6 types of screws, while a double-headed wrench can only be used for 2 types of screws.
An open spanner is equivalent to 2-3 dull spanners, which is equivalent to a movable spanner but can work quickly without adjusting the opening.
3．Long service life, can not be broken, and the front quick wrench is easy to break.
4．The manufacturing process is simple, and its cost is lower than that of a rigid hand.
5. Light weight, easy to carry and effortless.