Types and uses of pliers in real life

Pliers are hand tools used to clamp and fix processed workpieces or twist, bend, or cut metal wires. The shape of the pliers is V-shaped and usually includes three parts: the handle, the jaw and the mouth of the pliers.

The pliers are generally made of carbon structural steel, first forged and rolled into the shape of the pliers embryo, then subjected to metal cutting processing such as milling, polishing, and finally heat treatment.

The handles of the pliers are designed in three styles: straight handle, curved handle and bow handle according to the holding style. The pliers are often in contact with live conductors such as wires, so their handles are generally covered with protective tubes made of insulating materials such as polyvinyl chloride to ensure the safety of the operator.

There are many forms of pliers mouths, such as sharp mouth, flat mouth, flat mouth, round mouth, curved mouth and other styles, which can be adapted to the work needs of different shapes of workpieces. According to their main functions and nature of use, pliers can be divided into clamping pliers, wire cutters, wire strippers, pipe pliers, etc.

There are many types of pliers, and it has a wide range of uses. It is an indispensable hand tool for clamping and cutting workpieces in various industries such as assembly, repair and installation. But it has a common basic structure, that is, any hand pliers is composed of three parts: pliers head, pin and pliers handle. The basic principle of the pliers is to use two levers at a point in the middle to be cross-connected with a pin so that the two ends can move relatively. As long as the tail end is operated by hand, the other end can pinch the object. In order to reduce the force used by the user during operation, according to the mechanical lever principle, the pliers handle is usually made longer than the pliers head, so that a stronger clamping force can be obtained with a smaller force to meet the requirements of use.

The three parts of the pliers are as follows:

A pair of handles for holding. The pliers handle designed according to the ergonomic principle is convenient for safer and more comfortable holding. The connecting shaft, which is the connecting shaft point of the pliers. The connection point must move smoothly without any looseness, so that it can be easily opened or closed with one hand. The pliers head strap holds the pliers mouth or cutting blade. The blades of the pliers are finely ground into a suitable shape. The two cutting edges (with springs) must be very sharp and close to each other accurately to be easy to cut the wire.

This converts a small external force (such as the hand force exerted on the pliers arm) into a larger power, so that the pliers can effectively clamp or cut. When the external force exerted on the pliers arm increases with the leverage ratio, the force of the pliers mouth produces an external force for clamping movement. If a large external force is to be generated, the distance from the center of the riveting position of the pliers to the handle must be as long as possible, and the distance from the clamping or cutting mouth to the riveting center must be as short as possible. However, many pliers will not greatly increase the hand strength, because they only make it easier to work in difficult-to-handle places, such as: electronic equipment assembly and electronic and precision engineering applications.

Pliers are usually forged from alloyed and unalloyed structural steel. For general pliers, they are made of high-quality carbon structural steel with 0.45% carbon content. High quality and heavy duty pliers are made of high carbon content and/or alloying elements such as chromium or vanadium.

The origin of pliers in Europe can be traced back to more than one thousand BC, when people just started to cast iron. In the casting process, pliers can be used to hold hot iron blocks. The shape of the forged pliers in the past has remained unchanged until now. The types of pliers have expanded with the development of handicrafts, commerce and industrialization. There are 100 kinds of general pliers. Pliers for special applications are also increasing. Of course, these special pliers are not often available in the universal range. The only one in Germany, the monthly output of pliers exceeds 1 million, about 50% are exported. Most of them are general-purpose pliers, such as cutting pliers, wire cutters and water pump pliers.

Regarding functions, the differences are as follows:

①The cutting pliers can be used for cutting or trimming (side cutting pliers, front cutting pliers, trimming pliers, etc.).

② Wire cutters can be used for cutting and clamping (wire cutters, crane nose pliers, electronic pliers, etc.).

Regarding the splicing structure, the differences are as follows:

① Butt splicing, such as woodworking pliers. They are installed on the top of the pliers butt each other without milling and riveting.

② Single shear splicing, such as wire cutters. Milling the joints, milling half of the thickness, so that the two pieces of pliers are inserted into each other.

③ Sleeve type splicing, one handle is provided with a groove, and the other handle is passed through the groove and spliced ​​at the joint. Casing spliced ​​pliers-except for water pump pliers-are more difficult to manufacture from harder alloy steel, so the manufacturing cost is higher. Therefore, compared with the first two splicing methods, it is relatively less important.