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 the pliers.
The pliers are generally made of carbon structural steel. They are first forged and rolled into the shape of the plier’s embryo, then subjected to metal cutting such as milling, polishing, and finally heat treatment.
Basic meaning
The handles of the pliers are designed in three styles: straight handle, curved handle, and bow handle according to the gripping 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 types of pliers mouths, such as pointed mouth, flat mouth, flat mouth, round mouth, curved mouth, and other styles, which can be adapted to the needs of different shapes of workpieces. According to its main function and nature of use, pliers can be divided into clamping pliers, wire cutters, wire strippers, pipe pliers, etc.
Introduction
There are many types of pliers, and it has a wide range of uses. It is an indispensable hand tool for pinching and cutting workpieces in various industries such as assembly, repair, and installation. But it has a common basic structure, that is, any hand plier 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 be relatively movable. 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 the pliers can be opened or closed easily with one hand. The pliers head strap holds the plier’s 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 make it easy to cut the wire.
This converts a small external force (such as the hand force applied on the plier’s arm) into a larger power so that the pliers can effectively clamp or cut. When the external force exerted on the plier’s arm increases with the leverage ratio, the force of the plier’s 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. General pliers are made of high-quality carbon structural steel with a carbon content of 0.45%. 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 handicraft, commerce, and industrialization. There are 100 kinds of general-purpose pliers. Pliers for special applications are constantly increasing. Of course, these special pliers are not often available in the general-purpose range. The only one in Germany, the monthly output of pliers exceeds 1 million, about 50% of which 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.).
②Wire 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. The top of the pliers is butt-mounted with each other, without milling and riveting.
②Single shear splicing, such as wire cutters. Milling the joints, milling half 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 with harder alloy steel, so the manufacturing cost is higher. Therefore, compared with the first two splicing methods, it is relatively less important.
Features
Pliers generally include wire cutters, needle-nose pliers, and diagonal pliers. It is used to clamp or bend sheet-shaped, cylindrical metal parts and cut metal wires, and its side edge can also be used to cut thin metal wires.
Material: The pliers are made of high-quality chrome vanadium steel.
Forging: Hot forging forming technology using die forging.
Heat treatment: computer-controlled heat treatment technology is used to ensure the stability of hardness.
Surface treatment: surface polishing treatment.
Features: The cutting edge is subjected to a special heat treatment process to maintain the stability of the long-term shearing work.
Hardness: HRC40-48.
Shearing knife: meet DIN standards.
Precautions
①Use the pliers to operate with your right hand. With the jaws facing inward, it is convenient to control the cutting position. Use your little finger to stretch the middle of the two pliers handles to resist the pliers handles, and open the plier’s heads so that the plier’s handles are separated flexibly.
②The knife-edge of the pliers can be used to cut the rubber or plastic insulation layer of flexible wires.
③The blade of the pliers can also be used to cut wires and iron wires. When cutting No. 8 galvanized iron wire, use a knife to cut back and forth around the surface a few times, and then only need to pull it lightly to break the wire.
④The guillotine can also be used to cut hard metal wires such as electric wires and steel wires.
⑤The insulated plastic tube of the pliers can withstand a voltage of more than 500V, and it can cut wires with electricity. Don’t throw it around during use to avoid damaging the insulating plastic pipe.
⑥Do does not use pliers as a hammer.
⑦Do does not use pliers to cut double-stranded live wires, as they will short-circuit.
⑧When using pliers to wind the hoop to fix the cable, clamp the wire between the teeth of the pliers and wind it in a clockwise direction.
⑨It is mainly used for cutting single-strand and multi-strand wires with thinner wire diameter, as well as for bending single-strand conductor joints and stripping plastic insulation.
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