Combined pliers: features of selection and operation

Rare repairs in any area are not complete without such a widespread and versatile tool as pliers. The purpose of the pliers is to grip, manipulate and cut cables, cables of various kinds, wires.

Pliers are a multifunctional hand-held locksmith and assembly tool, which is designed to clamp and grip various workpieces and products that have different shapes.

Important parameters to consider when choosing such a tool are the items listed below.

• The choice of the purpose of the application. If combined pliers are planned to be used as a working hand tool, then you need to pay attention to models designed for professional use.
• The use of household varieties will not correspond to professional tasks, since such models do not have a sufficient margin of safety during operation with increased loads.
• Manufacturer's choice. High-quality tools, which are used correctly even under increased loads, can last for many years.
• How productive and functional they are. For electricians, for example, reliable electrical insulation is an important criterion.
• Pliers handles should be ergonomic, repeating the anatomical shapes of the hand. This approach will give its positive effect with prolonged monotonous work - the muscles of the hands will not tire so much.
• What color will the pliers be - in low light, a bright instrument is easier to spot among other instruments. As an option - the choice of a model, when painting the pens of which fluorescent paint was used, which glows in the absence of light.
• You need to choose pliers by squeezing the handle. If there is no tight and even coincidence of the notches on the working jaws, then you should not purchase such a tool.
• Non-original products have a lower cost, but the quality of such pliers will probably leave much to be desired, so they will not last long. In addition, they can fail at the most inopportune moment and injure the employee.

Of the secondary selection parameters, several more parameters can be noted.

• The appearance of the tool. It doesn't matter what decorative substances the instrument is finished with: chrome, nickel or something else. This has nothing to do with functionality or ergonomics.
• You should also not pay attention to additional functions. highly specialized models - they are unlikely to be used often, and they significantly affect the price.

A short video review of the Gross combination pliers.

The most demanded pliers are models with dimensions of 150 mm, 160 mm, 180 mm and 200 mm in length.

Pliers for use on electrical equipment with voltages above 1000 VAC and above 1500 VDC must comply with IEC60900.

As a rule, this tool is made of high quality grades of 8HF carbon steel. in accordance with GOST 5950-2000 or U7A in accordance with GOST 1435-99 using special technologies of hardening, heat treatment and finishing, which is a guarantee of their high strength, wear resistance and durability.Additional processing of the working cutting edges with high-frequency current gives them increased strength.

The hinge connecting the movable halves of the pliers allows them to move without significant play, even when experiencing high specific loads, since the tool uses a reliable precision connection. The ergonomic design of the handles, which are usually made with thermoplastic elastomers, guarantees a comfortable and secure grip. The protective and decorative coating of the pliers handles can be chemical oxide enamel of various colors or varnish.

If decorative handles are used in the product, then such a tool must be tested according to the recommendations of the GOST 11516-94 standard., while in the process of their manufacture it is necessary to use a non-crease, moisture- and oil-resistant, non-flammable, durable insulating substance. Shells, chips, cracks, bulges and other defects in the insulating material of the pliers handles are unacceptable, since they will reduce the mechanical and electrical protection of the tool.

The warranty period for the use of pliers is 9 months from the date of sale or from the moment the buyer received the tool in case of its pre-order.

This tool is made in two versions:

• pliers with elongated jaws and used for industrial purposes;
• pliers with shortened Linnemann jaws.

The planes of the clamping surfaces of the pliers are corrugated in accordance with GOST 21474-75.

A gap of more than 0.1 mm between the cutting elements of the pliers is not allowed.

Tool pivot clearances for one side of more than 0.3 mm are not allowed on the 125 mm pliers model. For other options, the maximum allowable gap is 0.4 mm.

When making pliers, the manufacturer must affix their well-readable markings to them. Other signs and markings are allowed at the request of the customer.

When manufactured in accordance with standards, the tool undergoes a series of tests.

Strength test of handles by applying a load with subsequent measurements of the deformations that have occurred with the tool.

Snack test. The state of the cutting elements and the cutting of wire samples made of different metals are assessed with the application of a certain force. At the end of the test, the cutting elements should not have burrs or any deformations that subsequently adversely affect performance.

Torsion tests. The plate clamped in the pliers is subjected to a torque of a certain force and the degree of deformation of the structure material is measured.

Electric current resistance tests. Insulated tool handles are immersed in water so that the level is 25 mm below the insulated edges, that is, the conductive parts of the pliers must not be in the water. Then a voltage of 10 kV / 50 Hz is applied for 180 seconds and the leakage current is measured (the norm is less than 1 mA per 200 mm of insulated pliers handles).

In conclusion, we can say that the choice of pliers must be made based on how they are planned to be used, and their characteristics and production standards in our country and abroad are more often observed by manufacturing companies that value their reputation. For this reason, purchasing such products from them is ultimately considered a more profitable event.