How to solder twisted copper wires

Rules for soldering copper wires - Welding Pros

There is wiring in every house. And the correct connection of wires is part of the safety of the electrical network and its trouble-free operation.

Installation of electrical wiring in an apartment or cottage involves connecting the wires of distribution boxes and switchboards. The safety of the electrical network and its trouble-free operation depend on how correctly and efficiently all connections are made.

Correct connection of electrical wires

Methods for connecting electrical wires

Electricians use the following methods for connecting wires:

  • twisted;
  • soldering;
  • using terminal blocks;
  • crimping;
  • with bolts;
  • plastic PPE;
  • “Wago” – spring terminals;
  • "nuts" made of plastic.

The choice depends:

  • from the material of the wire (cable) cores;
  • on the operating conditions of the electrical network (external or internal wiring, hidden or laid openly);
  • from the cross-section of the connected conductors;
  • on the number of cores in one connection.

The connection of the distribution box wires must be made in such a way as to ensure reliable contact and avoid heating the wires. Here is an overview of the above methods for connecting current-carrying conductors.

Features of using terminal blocks to connect electrical wires

The terminal block consists of a plastic housing, a brass or copper bushing with threads and screws located on both sides.

This device allows you to:

  • save on electrical equipment: the terminal block is cheaper than other connectors;
  • connect the wires securely;
  • connect cores of dissimilar metals (copper with aluminum);
  • reduce installation time.

Disadvantages of terminal connectors:

  • unsuitability for connecting more than two conductors;
  • difficulties when connecting aluminum conductors: if the screw is over-tightened, the metal may break;
  • unsuitable for use with multi-core wires.

The connection of electrical wires in the terminal block is carried out as follows.

The outer insulation is partially removed from the cables and the cores are exposed. The length of the bare conductor depends on the size of the terminal.

The length of the wire section without insulation is checked, for which you need to unscrew the terminal screw and insert the core completely into the hole. The excess is cut off with side cutters.

To improve contact, the copper wire is tinned. The connected cores are inserted into the terminals one by one and clamped with screws in several stages.

The reliability of the connection is checked.

Tip: in order to remove the insulation without damaging the core, it is recommended to use a special tool. If this is not available, only the surface layer of insulation is cut in a circle with a sharp knife, after which the wire should be bent along the cut line. After breaking, the insulation is removed with a light movement of pliers.

We use spring terminals to connect electrical wires

The connection of conductors with spring terminals is carried out using springs that press the contact plate to the metal of the core. The mechanism is driven by a special lever.

Wago type terminal connector

The Wago technology has a number of advantages over other installation methods:

  • allows you to connect aluminum wires with copper;
  • can be used to connect more than two wires;
  • allow you to switch wires in small junction boxes;
  • installation is carried out efficiently and in the shortest possible time;
  • conductor cores are not damaged;
  • After installation, it is possible to check the continuity of the circuit using a device probe or indicator through a hole in the housing.

In order to connect the wires using Wago terminals, it is necessary to remove the insulation so that the exposed wires are not visible, then insert the wires into the connector sockets and press the levers until they stop.

Note: Wago spring terminals are available in reusable and disposable versions. The latter, if it is necessary to repair the connection, are cut off, after which new connectors are installed.

Connecting conductors using PPE caps

The PPE cap is screwed onto the connection clockwise

The abbreviation PPE means “connecting insulating clamps”. The connector is designed as a spring located in a plastic housing. The spring securely holds the wires together, which creates reliable contact. Advantages of this method:

  • the ability to mark wires using colored caps: the “phase” conductors connect red PPE, “zero” – blue or white, “ground” – yellow or green;
  • fire protection: connector bodies are made of non-flammable plastic.

Important: connecting copper and aluminum wires using PPE is not allowed.

Crimping with sleeves

Connecting conductor cores with sleeves

The method consists of putting a metal tube (sleeve) on the cores freed from insulation, which is crimped with press pliers. As a result, the conductors are tightly connected to each other. The connection point is isolated.

Important: connections of aluminum and copper conductors may only be made using sleeves specially designed for this purpose.

Welding or soldering technology allows you to obtain a reliable connection of wires

The disadvantage of this method is the inability to monitor the integrity of the network after installation and isolation, as well as the non-repairability of such a connection. Additionally, a DIY soldering torch is dangerous to use.

An alternative to soldering wires is to weld them. The process involves the use of a welding machine.

Wire welding technology

When connecting copper wires this way, it is recommended that you try out a DIY copper wire soldering transformer before you begin. It is important to know that copper is smelted at a temperature of 1080 °C, but above 300 °C this metal becomes brittle.

In the absence of a special soldering device, use a conventional inverter welding machine. The step-by-step process of welding wires is as follows.

Up to 10 cm of insulation is removed from the ends of the wires.
The cores of the connected wires are tightly twisted together. The result should be twists approximately 5 cm long.

The ground cable of the inverter apparatus is connected to the twist closer to its beginning.
The current adjustment knob is set in the position from 30 to 90 A (at a voltage of 12 - 36 V): the value is selected depending on the cross-section of the wire and their number.

The carbon electrode of the welding machine briefly (no more than 2 s) touches the twist so that an arc is formed. As a result, a welded monolithic joint is formed at the tip of the twist. After complete cooling, the connection is insulated with heat shrink tubing or adhesive tape.

At the ends of the cores connected by welding, a monolithic alloy is formed

Connecting electrical wires by soldering

Soldering copper wires is an old, proven method that allows you to obtain a reliable electrical connection. The technology allows the installation of monolithic and stranded wires of various sections. There can be several conductors in one connection.

The work is performed using the following technology.

The insulation is removed from the ends of the connected conductors using a special device (approximately 5 cm).
The strands are tightly twisted together manually or using pliers (depending on the number of strands and their sections).

The twist is treated with flux or rosin.
This is necessary to improve the quality of soldering. On an open fire (using a gas burner or a gasoline blowtorch), a cup soldering iron (futorka) is heated red-hot. The cup of the futor is filled to the brim with tin-lead solder grade POS 30, POS 40 or POS 61.

The solder is heated to the point of fluidity.
The twist is briefly (up to 1 second) completely dipped into the futor cup, as a result of which the solder should completely cover the exposed wires.

After natural cooling, the twist is insulated with PVC adhesive tape or a plastic cap.
Important: soldering of wires should be done with safety glasses and tarpaulin gloves. During work, fire safety rules must be observed.

Soldering copper wires is performed as shown in the video.

Connecting wires with simple twisting

Wire connection diagrams in a distribution box for low-power electrical networks can be implemented by simple twisting without the use of additional fixing means. In this case, it is important that the twisting step is as small as possible, and its length is at least 20 mm. Only cores made of homogeneous metals are connected in this way: copper - with copper, aluminum - with aluminum.

It is not allowed to use this installation method in damp rooms and in wooden houses.

After twisting, the wire connection should look as shown in the photo

Walnut clamp

For connecting wires with a cross-section of 4 square meters. mm and it is more convenient to use a “walnut” clamp. It consists of a pair of specially shaped plates that are pressed together with screws at the corners. Advantages of the method:

  • ease of connection;
  • the ability to connect copper conductors with aluminum ones;
  • comparative cheapness of materials.

Important: the “walnut” clamp is not used in distribution boxes (dimensions do not allow). To ensure reliable contact, the screws must be tightened from time to time.

Using a bolted connection to connect electrical wires
To connect large cross-section wires, as well as to install grounding elements in an electrical panel, a bolted connection is used. The ends of the wires, freed from insulation, are screwed onto the bolt threads in a clockwise direction. The connection is pressed with a washer with an engraver and a nut, after which the bolt is isolated.

In conclusion, we suggest that you familiarize yourself with the training video (master class with expert comments).


If you have any questions on this topic, ask them to the experts and readers of our project here.


How to weld copper wires at home

Copper wires are more practical than aluminum wires; they are often used for wiring in private homes and laid when renovating apartments. Several ways of designing cable joints are allowed: they are secured with terminals or soldering.

Crimping or compression of the twist is allowed, but the most reliable connection is formed by molten copper. To weld copper wires on a line or in a distribution box, spot technology is used.

It is necessary to melt the twist to a homogeneous structure so that the resistance in the circuit does not increase. This is done for fire safety.

Features of welding copper wires

Copper melts well and is quickly saturated with hydrogen and oxidizes in the molten state. The melting point of copper alloys is no more than 1000°C. To protect the metal when welding copper parts, argon or carbon dioxide is used, but welding wires in a protective atmosphere is not economically feasible. For welding copper cables, conventional machines are used that generate direct or high-frequency alternating current and voltage from 15 to 30 V.

It is desirable that the operating current be regulated; to twist one core with a cross-section of 1.5 mm2, a current of 70 A is required; to connect three wires, the amperage will need to be increased to 90–100 A. To install copper wiring in a house with the connection of powerful electrical equipment, it is necessary to choose welding machines up to 120 A. If there is no optimal current, the arc will be interrupted and the electrode will begin to stick.

Soldering or welding copper wires - which is better?

The simplest and most effective soldering method is to immerse the contact point in molten solder. For small circuits this method is suitable. But it is not suitable for installing lines made of copper wires. Soldering with tin solders by weight requires skill; beginners cannot cope with such work, and there is a high risk of injury. Connecting wires with your own hands using contact welding is much safer.

Another advantage of welding is that the chemical composition of the wires does not change, and no solder particles get into the alloy. The electrical conductivity of the copper cable at the point of twisting does not change. Welding is faster than soldering; there is no need to pre-tin the contacts or select a soldering iron according to the power of the cable size. There are multi-core cords that cannot be soldered.

Welding has the only drawback: if you do not have the skills, you can damage the integrity of the insulation of the copper wire.

Welding machine

For welding copper wires, any current generator is used: transformer, rectifier, inverter. Resistance welding pliers are connected to car batteries, the two are connected in series, and the contacts are brought out to the electrodes. There is enough power to connect the cable to a 5 mm core. You can’t do a large volume with batteries; you need a welding machine.


The advantages of modern inverter devices are obvious:

  • they can weld wires of any cross-section;
  • they are not afraid of voltage “sagging” in the network, they reduce the risk of electrode sticking and burning of copper strands;
  • there are lightweight models that deliver current up to 150–200 A;
  • operate from a standard network, no need to connect to three-phase current.

Working with an inverter is easier than working with a transformer. For direct current welding of direct polarity, the plus is connected to the electrode holder, the minus to the copper wire being welded.


Bulky old-type devices are difficult to drag from place to place, but transformers are capable of generating current within 400 A. The transformer is suitable for working with direct current of direct or reverse polarity. They are used for welding copper busbars in distribution panels and connecting twisted conductors of large cross-section.

The transformer is connected in the same way as an inverter: “+” to the electrode, “-” to the twist. Transformants have good performance, but during operation they hum a lot, get hot, they are periodically turned off and allowed to cool. When turned on, they “sag” the network, but then the voltage stabilizes. When working with a transformer, this should be taken into account.

Based on a step-down transformer with a power of up to 150 A and voltage from 12 to 38 V, you can make a welding machine yourself from household appliances: you need to wind the number of turns of cable around it. You can calculate their number using tables.

If you include a diode bridge in the electrical circuit, it will stabilize the arc. The holder can be purchased at the store or a trolleybus contactor clamp can be used instead. Clamping conductive pliers are made from pliers - a contact terminal is screwed to one handle.

Be sure to ground the homemade device.

Technology for welding strands of copper wires

The connection consists of melting the welded conductors with an arc when passing current, the clamping device compacts the structure of the diffuse layer. It is worth considering the process of welding strands of copper conductors in more detail. Step-by-step instruction:

  1. The ends of the cable to be connected are cleaned and the insulation is removed at a distance of up to 7 cm so that the wiring is not damaged during operation.
  2. The cores or threads are folded in parallel, they must be tightly twisted together, the type of twisting does not matter, but when axially joining in the direction of the conductors to each other, it is more difficult to weld the twist.
  3. The length of the twist should reach 5 cm, excess fibers are cut off. The wires are placed between the contacts or in a homemade clamping device at a distance of 2–3 cm from the edge.
  4. After touching the conductors with the electrode, an electric arc occurs; it is held for no more than 2–3 seconds, depending on the thickness of the conductors.
  5. The copper is melted in the clamping device, creating a strong connection.
  6. The cooled connected conductors are wrapped with insulating tape or heat-shrinkable film is put on it.


Methods for connecting wires to each other

First of all, you must understand that different types of connections may be used in different conditions. And their choice depends on the specific task at hand.

For example, it is much more convenient to connect small-section wires up to 2.5 mm2 in a compact junction box with terminal blocks or clamps. But if we are talking about a groove or a cable channel, then the sleeves come first.

Let's consider the three most simple and at the same time reliable types of connections.

Let's start with the connection type PPE. It stands for:

It looks like a simple cap. Comes in different colors.

The cores are inserted into this cap and twisted together.

How to do it correctly, first twist the wires and then put on a cap or twist them directly with the PPE itself, is discussed in detail in the article “PPE cap for twisting wires.”

THIS IS INTERESTING:  How to solder correctly

As a result, thanks to PPE, you get a good old twist, only immediately protected and insulated.

On top of that, it has a spring-loaded contact that prevents it from coming loose.

In addition, this process can be slightly automated by using an attachment for PPE for a screwdriver. This is also discussed in the above article.

The next type is Wago terminal blocks. They also come in different sizes, and for different numbers of connected wires - two, three, five, eight.

They can connect both monocores and stranded wires together.
Moreover, this can be implemented both in different types of Vago, and in just one.

For stranded ones, the clamp must have a latch-flag, which, when open, easily allows you to insert the wire and clamp it inside after latching.

According to the manufacturer, these terminal blocks in home wiring can easily withstand loads of up to 24A (lights, sockets).

There are some compact specimens also available for 32A-41A.

Here are the most popular types of Wago clamps, their markings, characteristics and what cross-section they are designed for:

There is also an industrial series for cable cross-sections up to 95mm2. Their terminals are really large, but the principle of operation is almost the same as that of small ones.

When you measure the load on such terminals, with a current value of more than 200A, and at the same time you see that nothing is burning or heating, many doubts about Wago products disappear.

If you have original Vago clamps, and not a Chinese counterfeit, and the line is protected by a circuit breaker with a correctly selected setting, then this type of connection can rightfully be called the simplest, most modern and convenient to install.

Violate any of the above conditions and the result will be quite natural.

Therefore, there is no need to install wago at 24A and at the same time protect such wiring with a 25A automatic. In this case, the contact will burn out if overloaded.

Always choose the right terminal blocks for your car.

There is also a fairly old type of connection, such as terminal blocks. ZVI – insulated screw clamp.

In appearance, this is a very simple screw connection of wires to each other. Again, it comes in different sections and different shapes.

Here are their technical characteristics (current, cross-section, dimensions, screw torque):

However, ZVI has a number of significant disadvantages, due to which it cannot be called the most successful and reliable connection.

Basically, you can only connect two wires to each other in this way. Unless, of course, you specifically choose large pads and shove several wires there. What to do is not recommended.

This screw connection works well for monocores, but not for stranded flexible wires.

For flexible wires, you will have to press them with NShVI lugs and incur additional costs.

You can find videos online where, as an experiment, transition resistances on different types of connections are measured with a microohmmeter.

But we should not forget that this experiment refers to “fresh contacts.” Try making the same measurements after a year or two of intensive use. The results will be completely different.

Often a situation arises when it is necessary to connect a copper conductor to an aluminum one. Since the chemical properties of copper and aluminum are different, direct contact between them, with access to oxygen, leads to oxidation. Often even copper contacts on circuit breakers are susceptible to this phenomenon.

An oxide film forms, resistance increases, and heating occurs. Here we recommend using 3 options to avoid this:

  • bolt + nut with steel washers

They remove direct contact between aluminum and copper. The connection occurs through steel.

  • special Wago terminal blocks with paste

The contacts are separated from each other in separate cells, plus the paste prevents the access of air and prevents the oxidation process from developing.

  • use of copper-aluminum adapter sleeves GMA

The third simple way to connect conductors is crimping with sleeves.

GML sleeves are most often used for joining copper wires. Deciphered as:

For connecting pure aluminum - GA (aluminum sleeve):

To switch from copper to aluminum, special adapters GAM:

What is the crimping method? Everything is quite simple. Take two conductors and strip them to the required distance.

After this, on each side of the sleeve, the conductors are inserted inside, and the whole thing is crimped with press pliers.

Despite its obvious simplicity, there are several rules and nuances in this procedure, if not followed, you can easily ruin a seemingly reliable contact. Read about these mistakes and rules on how to avoid them in the articles “5 Rules of Crimping” and “Crimping Insulated Tips, Sleeves and Terminals”.

To work with conductors of large sections 35mm2-240mm2, a hydraulic press is used.

Up to cross-sections of 35mm2, you can also use a mechanical one with a large span of handles.

The sleeve must be crimped two to four times, depending on the cross-section of the wire and the length of the tube.

The most important thing in this work is to choose the correct sleeve size.

And in this way you can connect several conductors at one point at the same time. In this case, only one sleeve will be used.

The main thing is to completely fill its internal space. If you are crimping three conductors at the same time, and you still have voids inside, then you need to “fill” this free space with additional pieces of the same wire, or with conductors of a smaller cross-section.

Only after this can you press.

After crimping, such a connection must be insulated. The most convenient way to do this is with a heat-shrinkable tube HERE.  

There are tubes with an adhesive base. When heated, this glue flows out and ensures the tightness of the connection.

Insulation using a thermal tube is also a fairly simple process. In the absence of a gas burner or hair dryer, even a lighter is sufficient for small sections.

Sleeve crimping is one of the most versatile and reliable connections, especially when it is necessary to extend the cable, including the input cable.

In this case, the insulation turns out to be almost equivalent to the main one, when also using the outer tube HERE as a casing.
Of course, you won’t use either PPE or Wago for these purposes, but GML cartridges are just the thing! At the same time, everything comes out compact and can be easily reduced, either in a groove or in a cable channel.

In addition to all the above connection methods, there are two more types that experienced electricians rightfully consider the most reliable.

  • electric welding
  • soldering wires

However, this type of docking cannot be classified as simple. It requires special equipment, which even 90% of electricians often do not have available.

And even with its help it is not always possible to connect an aluminum monocore wire with a flexible copper stranded one. In addition, you are forever tied to an outlet or extension cord.

What if there is no voltage or generator nearby? More details

At the same time, on the contrary, 90% of electrical installers have elementary press pliers. It is not necessary to purchase the most expensive and sophisticated ones for this.

For example, batteries. It’s convenient, of course, just walk and press a button.

The Chinese counterparts also cope well with their task of crimping. Moreover, the entire process takes no more than 1 minute.


How to solder strands of copper wires

When I need to connect copper wires in a junction box, I twist and solder them. However, at the moment there is a lot of debate about reliability: some claim that the soldered connection is the most reliable, while others criticize soldering and recommend spring terminal blocks. It is worth noting that the supporters of the soldering iron are experienced, Soviet-trained electricians.

Today we will not find out which is better - in my opinion, an objective assessment of the quality of connections will be a comparative test at extreme currents, perhaps in the future we will conduct a similar test. But now let's talk about how to twist wires in junction boxes and actually solder them.

I would like to note: despite the fact that the process is simple and easy to master, it must be performed with care and accuracy. After all, all fires, as a rule, are caused by poor contact in one place or another.


To perform all operations we need the following tool:

Soldering iron 100-150 W with a copper tip. Ordinary, without frills in the form of a fireproof sting and other things. The sting can be straight or curved.

We will also need side cutters (nippers), pliers (pliers) and a construction knife. When working with thick twists, where, for example, 4 mm² cores will be present, additional pliers will be needed.

An optional tool includes pliers for stripping insulation: you can do without them, but with this tool things go faster.

Solder selection

Choosing the right solder for soldering twists is the most crucial moment. The final result depends on the solder. In the process of using different brands of solder, I tried to identify a pattern between the quality of soldering and the percentage of tin. However, such a relationship could not be found.

The only thing that can be said with complete confidence is that the solder must have flux inside. This is not surprising: the soldering method does not require the application of flux to the twists, but flux is necessary.

It is most convenient to use solder in a wire 1mm or so thick. It is sold in spools or plastic tubes.

By and large, you will have to choose solder by trial and error; I don’t see any other method. Well, here are a few examples of solders from several manufacturers:

This solder is well suited for soldering twists. And it’s better not to take the one below - it solders thin strands of 2 wires 1.5 mm² well, but it will only ruin thicker strands.

Here's another pretty good REXANT solder:

When choosing solder for the first time, the best option would be to buy a small tube for testing. Well, remember which of the purchased brands soldered well and which ones poorly. Actually, this is such a simple science.

In addition to solder, it is good to have a cleaner on hand - regular alcohol. Many copper strands, even new ones, are covered with layers of oxides or other deposits that make soldering difficult.

A good cleaner option is TAGS flux - it perfectly cleans the surface of copper conductors and in addition helps the soldering process.

Twisting wires

So, all wires are stripped of the general insulation that protects the entire cable. For each individual core, the twist length plus a small margin is taken - the base of the twist must be twisted with insulated cores. In general, you should try to put extra centimeters of wires in the box just in case.

Tip: always try to put more wires in the junction box, even taking into account the twists already made. Perhaps sometime in the future new lines will be added here or some repairs will be made. It would be good practice to consider the repairability of the boxes, even if you are confident in the reliability and quality of your work.

For the twists themselves, the cores are stripped to 10 centimeters - after twisting, the excess will be bitten off with side cutters. The final twist length of bare wires must be at least 4 cm. If installation is carried out in spacious junction boxes, the length of the twists can be increased to 7-8 cm. The main thing is that the twists fit into the box without bending.

But I got ahead of myself a little: before twisting the exposed wires, you need to wipe them thoroughly with a cloth soaked in alcohol or TAGS flux. After processing, the surface of the copper should have a uniform yellow color without dark areas - only then can twisting be done. If the veins are covered with too thick oxide, then before wiping they can be treated with fine sandpaper.

When soft, stranded conductors are present among the wires being twisted, they should be cleaned of oxides with special care.

Twisting is done with pliers so that a few centimeters of insulation also become part of the twist. You should tighten it with sufficient force, but you must not overdo it and not break any of the wires. Here it is recommended to first practice on test twists and “feel” the material.

When twisting a large number of wires or when the cross-section of the wires is large (4 mm² for example), the base of the twist must be held with additional pliers.

When the twists are twisted, they need to be shortened with side cutters to the length we need. Shorter than 4 cm is not recommended.

The junction box is twisted, you can start soldering.


While the soldering iron is heating up, you need to “apply” solder to the twists. To do this, solder wire is wound onto each twist in increments of 1-3 mm. The winding pitch depends on the total thickness of all twisted wires and is found experimentally. The solder should be wound tightly so that it fits as tightly as possible to the copper surface.

If the twist contains stranded conductors, then more solder should be wound than usual. Stranded wires require much more tin - you need to take into account the number of flexible conductors in the total volume.

Using a heated soldering iron, touch the edge of the twist and wait until the solder melts. When melting the solder, we move the soldering iron to the base - the solder should melt before the soldering iron reaches its melting point. Key point: the soldering iron heats the metal, and the metal in turn melts the solder. By the way: it is not necessary to move the soldering iron from the edge to the base of the twist; you can do the opposite - from the base to the edge.

The solder should fill all the voids between the conductors and solder all the twists. Visually - the solder should be visible from all contacts of the cores with each other. Small strands are completely covered with solder, while larger ones are covered with solder where the cores touch each other.

Molten solder will definitely drip down, so you need to take all necessary measures to protect both yourself and the surrounding area.

If there are doubts that the solder has filled all hard-to-reach places, then soldering can be repeated again. To do this, you need to wipe the soldering area well with alcohol or TAGS, wind the solder and repeat everything. In such situations, the quality of the solder immediately becomes evident: the “crappy” solder will never be able to solder the second time.

After soldering, the strands are ready for insulation; they can be “wrapped” with electrical tape or heat-shrink tubing. Since we did not use soldering acid or other aggressive fluxes, there is no need to wash the soldering areas. When laying them in place, you should avoid bending the soldered areas.

In conclusion, I would like to say that soldering connections in boxes is a fairly simple matter. However, you will have to practice a little first and perhaps try several different solders.

One of the most reliable methods of connecting wires is soldering. This is a process in which the space between two conductors is filled with molten solder. In this case, the melting temperature of the solder must be lower than the melting temperature of the metals being joined. At home, soldering is most often used with a soldering iron - a small device powered by electricity. For normal operation, the power of the soldering iron must be at least 80-100 W.

THIS IS INTERESTING:  How and with what to solder a radiator

What you need for soldering with a soldering iron

In addition to the soldering iron itself, you will need solders, rosin or fluxes; it is advisable to have a stand. While working, you may need a small file and small pliers.

Most often you have to solder copper wires, for example, on headphones, when repairing household appliances, etc.

Rosin and fluxes

To get a good connection between the wires, it is necessary to clean them of contaminants, including oxide film. While mono-cores can still be cleaned manually, multi-core conductors cannot be cleaned properly. They are usually treated with rosin or flux - active substances that dissolve contaminants, including oxide film.

Both rosin and fluxes work well, but fluxes are easier to use - you can dip a brush into the solution and quickly process the wires. You need to put a conductor in rosin, then heat it with a soldering iron so that the molten substance envelops the entire surface of the metal. The disadvantage of using fluxes is that if they remain on the wires (and they do), they gradually corrode the adjacent sheath. To prevent this from happening, all soldering areas must be treated - the remaining flux must be washed off with alcohol.

Solders and fluxes for soldering copper wires with a soldering iron

Rosin is considered a universal remedy, and fluxes can be selected depending on the metal you are going to solder. In the case of wires, this is copper or aluminum. For copper and aluminum wires, use LTI-120 flux or borax.

A homemade flux made from rosin and denatured alcohol (1 to 5) works very well, and it’s also easy to make with your own hands. Add rosin to the alcohol (preferably dust or very small pieces of it) and shake until dissolved.

Then this composition can be used to treat conductors and strands before soldering.

Solders for soldering copper wires with a soldering iron use POS 60, POS 50 or POS 40 - tin-lead. For aluminum, zinc-based compounds are more suitable. The most common are TsO-12 and P250A (made of tin and zinc), grade A (zinc and tin with the addition of copper), TsA-15 (zinc with aluminum).

Convenient to use solder with rosin

It is very convenient to use solders that contain rosin (POS 61). In this case, there is no need to pre-treat each conductor in rosin separately. But for high-quality soldering, you must have a powerful soldering iron - 80-100 W, which can quickly heat the soldering area to the required temperatures.

Auxiliary materials

In order to properly solder wires with a soldering iron, you also need:


How to solder twisted copper wires

Village65, December 25, 2017 in Paika

Create an account or log in to comment

You must be a user to leave

Create an account

Register for an account. It's simple!

To come in

Already registered? Sign in here.

There are currently 0 users on the page

There are no users viewing this page.

What tools and materials will be needed?

The choice of tools and materials we need will be determined by our specific goals, as well as the soldering methods used. The main tool used is either an electric soldering iron or a gas torch. Well, then there will be, in general, a standard soldering kit. We will need:

  1. Knife for cutting wire insulation - do not forget to sharpen it or use a stationery knife. You can also make an electrician's knife with your own hands.
  2. Pliers for twisting conductors.
  3. Solder and flux. Flux is a substance with which we remove oxidation from the surface we solder. Solder is what is used to directly solder the wires.
  4. File – a fine file will do.

When soldering wires with a soldering iron or gas torch, different solders and fluxes can be used. So, for copper conductors you need solder based on a mixture of tin and lead - these are solders of the POS-40, POS-50, POS-60 brands. The following grades are suitable for soldering aluminum wires: P-250A (zinc and tin), TsO-12 (zinc and tin), TsA-15 (zinc and aluminum), A (zinc, tin, copper).

Rosin is used as a flux - an organic material containing a mixture of resin acids from coniferous trees. Rosin is the most common and inexpensive option. There are also methods of soldering with acid as a flux, but it is not recommended to use them because they are harmful. In addition, acid causes corrosion on the twist over time.

Let's solder!

When all the necessary tools and materials are ready, we get to work. Let's consider the technology of soldering copper wires in a junction box. At home, the most common connection method is soldering twists of single-core conductors. We strip them of insulation - remove 4-5 cm from each end.

For good quality twists, you should twist them tightly and crimp the ends with pliers. We talked about how to make a good twist in a separate article. Just don’t overdo it, otherwise you may break off the current-carrying wire.

We take a soldering iron in our hands, which should be warm enough, and begin to saturate our twist with rosin so that it penetrates between the wires as best as possible. Then solder, consisting of tin and lead, is applied to the soldering iron tip, and by gradually heating the joint, we achieve uniform application of solder.

It should penetrate well between the wires. When they “paint” silver, they can be considered tinned. You can find out more about how to tin wires in our corresponding article.

To tin a stranded copper conductor, you need to twist all the small strands well into one strand and tighten them with pliers. Then apply rosin with a soldering iron first, and then the desired solder.

A distinctive feature of soldering aluminum wires is the high degree of oxidation of aluminum in air. And if the wires oxidize, then applying solder to them during electrical installation will be problematic. Therefore, you will have to constantly mechanically clean the surface from oxidation and at the same time perform tinning. A gas burner is used for heating, and the flux is selected based on the soldering method and the cross-section of the wire.


How to solder twisted copper wires - Metalworker's Guide

Laying electrical wiring in a house involves connecting wires; from the main network you will need to make branches necessary to provide power to electrical appliances.

How to make a wiring connection correctly

Connecting wires is required everywhere in rooms, in cars, devices and mechanisms, wherever there are wires. Today the following methods are used:

  • Twisting;
  • Welding;
  • Soldering;
  • Using special blocks, terminal blocks;
  • Using self-clamping terminal blocks;
  • Using PPE caps.

Further in the article we will talk about the simplest way to connect wires - twisting; any home craftsman will be able to put it into practice, for example, when installing temporary wiring is required.

What you need to know about twisting

Take a close look at the photo of twisting wires, you will see that it can be done in different ways. You will need to prepare tools: a knife to strip the insulation, pliers to make the connection reliable, and you will also need electrical tape to insulate the twisted area.

Method - twisting wiring with protected ends

Expose the wires by at least 5 cm, cross the ends not protected by insulation, clamp the resulting cross with pliers and twist them together using a rotational movement.

Bend the resulting twist so as to direct it parallel to the wire, and insulate everything.

Twisting method with winding

Strip the wires at the ends and bend them slightly in the middle, hooking the wires together at the bend. Next, alternately wrap the ends of one wire around the other.

To fix the windings and make the connection more reliable, use pliers, tighten everything and carefully insulate it.

Method of connection with the bandage

You need to know how to twist the wires correctly in this case: you will also need to prepare a bare piece of wire.

Before connecting, the wires are stripped and placed side by side so that the stripped ends touch. Use the prepared additional piece for a bandage - use it to wrap the wires.

A common method is groove twisting

First, familiarize yourself with the sequence of steps on how to twist wires with your own hands. Bend the ends of the wire into small hooks, hook them together, and wind one wire around the other.

Insulate the resulting twist to ensure human safety, reliable contact, prevent current leakage and prevent short circuits.

Professionals say that these types of wire twisting can be made more durable by using the following recommendations:

Twisted contacts are additionally connected by soldering or welding, as a result the contact acquires maximum reliability and is almost impossible to break. It is preferable to use soldering when both wires of the connection have a large cross-section.

WAGO terminals greatly facilitate connection, making it more efficient; they are needed when you have to figure out how to twist copper wires with aluminum ones. The whole procedure will take place quite quickly, while the “vags” allow you to connect wires of different cross-sections, the contact will be reliable and durable.

If a home handyman is faced with the task of connecting wires in an electrical outlet or lamp, use WAGO terminal blocks.

Thanks to PPE clamps, the reliability of the connection increases significantly, making it as safe as possible. These products have a low price, so they are available at any electrical store.

Wires twisted together should not be immediately closed using a junction box. It is better to observe how the electrical network works for several hours, after which it is recommended to check the temperature at the mounting location. If the connection gets very hot, you need to do everything again: most likely, the contacts are unreliable.

The twist itself is not waterproof, so it is better to take a box to connect the wires inside the wall; if without it, then the twist wires will need to be insulated using cambrics.

All you have to do is determine for yourself which twisting method is better and consider methods for isolating nodes.

What a DIYer should know about soldering and welding

Soldering is considered simply an improvement on twisting; the wires are first twisted and then soldered using a soldering iron with solder. Advantages of soldering:

  • Increased twist strength;
  • Reduced resistance, which means the twisting area will not heat up.

Multi-core copper wiring can be easily soldered, but this method is not suitable for all wires, with the exception of twisting aluminum wires. Since soldering is fragile, you cannot be careless when performing it, otherwise you will end up with a poor-quality connection.

Welding is another method that improves twisting and increases reliability, but is also not suitable for aluminum wires. It is used for multi-core copper cables with a large cross-section; welding reliability is considered higher than soldering.

When using welding, the possibility of weakening of the twist cannot be ruled out; under the influence of high temperatures, the performance characteristics of the metal can change.

Insulation methods

Wire insulation is carried out using various types of electrical tape; it is necessary to insulate the twisted area and a section of insulated wires equal to at least 2 or 3 cm. Then it will be possible to make high-quality insulation that protects against unwanted contact with moisture; also for this purpose, special thermal tubes are additionally used.

Insulation with thermotube

A tube of the required length is put on one core before twisting.

Twisting is performed, after which the thermotube is moved to the junction of the contacts.

It is necessary that the tube adheres to the wiring as tightly as possible, so it is heated a little with a lighter. Under the influence of high temperature, the heat tube will shrink, and it will be possible to ensure a tight grip on the wiring.

The advantages of all kinds of twists lie in the simplicity of their execution; despite the minimal equipment, they have proven themselves to be quite reliable connections.

When high-quality insulation is made, for which good electrical tape is used, the service life of the twist will be quite long. This connection is convenient to use: it is detachable, which means that if necessary, the wires can simply be twisted again.

Twisting is used in loose electrical wiring that sag; this method has been adopted by motorists, since the wiring in the car is constantly exposed to vibration.

Among the disadvantages of twisting, the following should be noted:

It is not possible to connect wires having different cross-sections; in such a connection, as a rule, there is a very high resistance, which causes constant heating of the wires and melting of their insulating layer.

It is difficult to twist together multi-core cables, which are soft and may break under any tension.

When there are several insulated wires in the wiring, due to the fact that each core is insulated separately, the total thickness can be very large.

Twisting is not suitable when it is necessary to connect wires made of different materials - copper and aluminum.

When choosing a method, it is important to take into account all sorts of nuances; only then will you be able to get a high-quality connection with your own hands. Twisting must be done after turning off the power supply for safety reasons.

Photo of wire twisting


Welding copper wire: a review of methods and equipment. Soldering or welding copper wires - which is better?

The most important task when connecting any electrical contacts is to ensure their minimum resistance. If the contact is poor, the resistance between the copper wires increases significantly, resulting in heating of the cable.

There are many ways to connect contacts, but welding copper wire is considered the most reliable and effective. This technology allows you to monolithically connect all wire strands, thereby achieving the lowest possible electrical resistance.

As a result, heating of the wires is eliminated, therefore, the level of fire safety is significantly increased.

Wire connection methods

Copper is the main material of conductors. Due to the physical and chemical properties of this material (high plasticity, lack of elasticity), working with it has its own characteristics. The rules for electrical installations state that operations for connecting, branching and terminating cable cores and wires can be performed using soldering, welding, crimping or clamping (bolt, screw, etc.). Each of them has its own characteristics, which will be discussed below.

Connecting wires by twisting

Simple twisting of wires is prohibited by the PUE, since this is the most ineffective, short-lived and fire-hazardous connection. Despite this, home craftsmen never stop using this method, although the consequences of such “handicraft” can be the most disastrous.

Twisting wires has one important drawback: copper connections become deformed and weakened over time, eventually finally failing due to high contact resistance.

It should be remembered that the twisting method can only be used in exceptional cases, if it is necessary to urgently restore the power supply, and other methods are not available in a particular situation. It is very important to take care of the quality, safety and reliability of the connection.

It is strictly prohibited:

  • Connect wires made of different materials (aluminum and copper);
  • Connect a single-core copper wire to a stranded one.

The twisting process looks like this:

  1. Remove insulation from the wires at a distance of 6-8 cm from the edge;
  2. Place one wire on top of the other crosswise and twist as tightly as possible. If the cross-section of the copper wire is more than 1 sq. mm, this operation is performed using pliers.
  3. Use wire cutters to cut off the remaining ends of the wires.
  4. Insulate the twist using special insulating materials (PVC or heat-shrinkable tubes, caps) or several layers of insulating tape. The insulation must cover the insulating layer of the wires.
THIS IS INTERESTING:  What is needed to solder a wire


This method is a process of connecting wires by crimping them with a special tubular sleeve or tip. These devices are used if the cross-section of the copper wire is 2.5-240 square meters. mm. The undeniable advantages of crimping technology are the speed and accuracy of the work, as well as the subsequent durability and safety of the connections.

For crimping, a special tool is used - mechanical, hydraulic or electric pliers or professional crimping presses. The selection of sleeves is carried out taking into account the cross-section and number of connected wires.

After removing the insulation and stripping the cores, quartz-vaseline paste is applied to them, a sleeve is put on and crimped. The pressed sleeves are insulated.

Crimps and terminal blocks

The use of various crimps and terminal blocks is quite widely practiced when connecting electrical sockets, switches, lighting fixtures, as well as when installing distribution boards. These devices allow you to carefully and quickly connect a single-core copper wire, however, a stranded wire cannot be clamped into a screw clamp without prior soldering or crimping with a tubular tip.

The indisputable advantages of screw terminals include the ability to connect aluminum wires to copper wires, as well as the absence of the need for subsequent insulation of contacts.

However, this type of connection is not without its drawbacks. It requires periodic maintenance, which consists of tightening the clamping elements. Copper is a very soft material, prone to “leakage” under load.

Even if connections are made using rigidly spring-loaded self-clamping terminal blocks, due to the too small area of ​​contacting surfaces under heavy loads, the spring elements are heated and released, as a result of which their elasticity decreases along with the quality of the connection.

Soldering VS welding

To ensure good contact, soldering or welding of copper wires is most often used. Which of these methods is better? Definitely welding. The fact is that soldering is a rather labor-intensive and time-consuming process, especially if you need to connect a multi-core copper cable.

Plus, soldered joints are destroyed over time due to the presence of a third, looser and fusible metal - solder.

The presence of transition resistance at the junctions of different alloys contributes to the occurrence of destructive chemical reactions and other negative processes.

When copper wire is welded, the concept of “contact” disappears altogether, since the connection is made monolithic from the same type of metal. Naturally, such connections are characterized by record low resistance, due to which virtually no heat is generated.


The highest quality and safest connection is formed by welding copper wire. The resistance at the point of contact of the wires does not exceed their standard resistance. This method does not require much time and is considered relatively simple. With minimal skills and knowledge, welding copper wires at home is quite doable.

When carrying out welding work, all fire and electrical safety rules must be strictly observed. To avoid burns and eye injuries, be sure to use personal protective equipment - special protective clothing and gloves, a welding mask or goggles.

Welding equipment

Connecting wires using welding is performed using various types of devices. It is most convenient to use an inverter machine for welding copper wires, since devices of this type are characterized by small dimensions and weight, economical energy consumption and a wide range of welding current adjustments. Their advantages include the ability to ensure stable combustion of an electric arc.

If a significant amount of electrical installation work is planned, then purchasing an inverter-type welding machine will be quite appropriate and justified. In addition, this equipment will probably not remain “dead weight” in the future.

Features of the process of welding copper wires

Welding of copper wire can be carried out using either alternating or direct current at a voltage of 15-30 V. It is very good if the device has the ability to adjust the current.

For example, to weld two copper wires with a cross-section of 1.5 square meters. mm, 70 A is enough. To weld three wires with the same cross-section, the current must be increased to 90 A. The connection of three wires with a cross-section of 2.5 sq. mm will require from 80 to 100 A, and for welding five similar wires - 120 A.

If the optimal welding current is selected, the electrode does not “stick”, and the arc burns quite steadily.
To weld copper wires, carbon-copper “pencils” (electrodes) are used.

If there are none, then it is possible to use carbon rods from finger-type batteries.

Welding technology

The ends of wires 5-6 cm long are cleared of the insulating coating and twisted, starting from the insulation cuts, leaving 5-6 mm untwisted at the end of the twist. These ends must be straightened, folded parallel and pressed against each other.

When twisting three or more wires, you still need to leave only two free ends at the end, and cut off the rest at the last turn of the twist. If the welding machine is not powerful enough, such twisting will make it easier to form a melt ball.

If there is sufficient welding current in the machine, simple twisting can be performed.

Next, the twist is clamped using a welding clamp. If this device is not available, you can use regular old pliers.

The prepared joint is welded with a carbon electrode. In the welding process, copper wires are melted at the ends that are left untwisted until a molten ball is formed. To ensure reliable mechanical and electrical contact of the wires, the melting zone must reach the twisting point.

The duration of welding should not exceed 2-3 seconds, otherwise the insulation of the wires will melt. After the connection has completely cooled, it is insulated using several layers of electrical tape or special caps, PVC or heat-shrinkable tubing.


Technology of soldering wires and cable cores

Soldering wires is a method that allows you to obtain good contact conductivity results. Reliable connection of wires when installing electrical wiring requires special attention, because the conductivity of the contact and, as a consequence, the fire safety of the building as a whole depends on this. There are different ways to connect wires. Welding is the most reliable method, but it requires certain equipment and is quite labor-intensive.

Types of twisting wires for soldering.

Required tools and materials

To perform soldering work you will need the following tools:

  • an ordinary household soldering iron with a power of 40-100 Watts (you can use a soldering station on which it is easy to adjust the temperature of the soldering iron tip, which is very convenient when soldering);
  • knife for stripping insulation;
  • rosin for tinning surfaces;
  • solder for soldering various metals; you can also use various acid-free fluxes;
  • pliers for twisting;
  • a small file for cleaning the soldering iron tip.

Solder materials.

Soldering copper and aluminum wires with a soldering iron or gas torch is somewhat different, with a special difference in the solders used for these purposes. For soldering copper wires, lead and tin compounds are used:

For soldering aluminum wires use:

  • TsO-12 (zinc-tin);
  • A (zinc-tin-copper);
  • P250A (zinc-tin);
  • TsA-15 (zinc-aluminum).


Work order

Let's take a closer look at the soldering process for these types of materials. Different methods of connecting wires involve the use of different fluxes and soldering compounds, depending on the material.

The soldering method is usually used when connecting copper wires up to 10 mm2; cross-sections up to 6 mm2 are usually twisted together before soldering.

Connecting single-wire aluminum conductors by soldering double twist with a groove: 1 - double twist; 2 - solder stick; 3 - propane-butane burner.

Here's what you need to do to ensure quality work in this case:

  • the conductors are stripped of insulation to a length of 5-6 cm;
  • using a heated soldering iron, cover the surface with a layer of flux or rosin (rosin does not work well on an oxidized surface; when penetrating deeply into the twist, it is necessary to achieve complete replacement of rosin with tin);
  • by heating the wire with a soldering iron with solder on the tip, achieve a uniform coating of the surface with a layer of solder;
  • when soldering twists, ensure that all irregularities are filled with solder and the surface of the twist is covered with it;
  • After soldering is completed, all twists are insulated using special nozzles, heat-shrink tubing or electrical tape.

The main difference between aluminum soldering is the high rate of surface oxidation upon contact with ambient air. The oxide film prevents reliable adhesion of the solder to the metal. When soldering aluminum, the oxide should be mechanically removed and the surface should be tinned at the same time. The technology for connecting aluminum wires depends on the cross-section of the wires and the type of flux used; a gas burner is usually used for heating.

Let's consider the procedure for performing soldering work on cores with a cross section of 4-10 mm2:

  • the ends of the cores are cleared of insulation to a length of 5-6 cm;
  • the conductors are cleaned with a knife, sandpaper or a file until a metallic shine is obtained;
  • the cores are overlapped using the double twist method, making a groove in the middle, at the point of contact;
  • heat the joint to a temperature close to the melting point of the solder;
  • Without removing the flame, rub the groove with a stick of special solder;
  • under the influence of friction, the oxide film is removed and the groove is tinned with solder;
  • all sides of the twist are treated in the same way, filling it with tin;
  • after soldering, clean the joint by wiping the surface with gasoline;
  • the cleaned surface is covered with asphalt varnish and a layer of electrical tape.

Soldering wires is not particularly fast in installation, but the high quality of the contacts obtained, the durability and reliability of the connections have allowed this method to become widespread in electrical installation work.

Everyone has had to deal with the problem of broken wires in equipment. It’s unreasonable to take such a small thing to a workshop; it’s easier to master the soldering technique, which will help you repair household equipment at home.

The essence of technology

There are several methods for soldering wires, but for beginners, the manual method is recommended. This option is suitable for connecting metal conductors; for propylene and other plastics, a different technology is used.

The soldering process is absolutely accessible and understandable. The connected ends are treated with a special substance and then fixed with solder. The melting point of the solder should be lower than that of the metals used in the conductors. High-quality soldering can withstand a weight exceeding the material of the conductors.

Soldering time is considered to be the period from the heating of the solder until it completely hardens. The total duration of creating one connection is 4-5 minutes.

What you need for soldering

To solder the wires you will need a soldering iron, solder and flux. It is better to carry out work on a wooden stand. For a soldering iron, you need to prepare a stand in advance so that the hot tip does not damage the surface of the table.

Any scraper is suitable for cleaning; you cannot use sandpaper with coarse stones. Before carrying out work, the surfaces need to be degreased, so it is worth preparing another alcohol solution and cotton pads or swabs.

For convenience, you should also prepare tweezers and safety glasses. The first tool will help connect thin elements, and glasses will prevent eye injury. During the soldering process, hot springs or wires may jump off, which will lead to various problems. Protection will ensure the master's safety.

Sequence of soldering wires

The technological process of soldering two thin metal conductors consists of the following steps.

1. Cleaning the surfaces of conductors, removing corrosion and other contaminants. The process is carried out carefully until the metal shines. Any third-party attack will make the connection unreliable.

2. The stripped ends of the conductors are coated with flux. This is a special substance that removes oxide fragments well and also prevents oxidation of wires during operation. When choosing a flux, preference should be given to solid and paste-like substances; liquid is of little use in this matter.

3. Using a soldering iron, the solder is melted and an even thin layer is applied to the ends of the conductors. The solder should bond well to the metal.

4. Connect the wires using temporary twist or tweezers. An alternative is to use a vice.

5. Applying flux to the joint to prevent the formation of rust under the solder.

6. Melt the solder with a soldering iron and distribute the substance around the joined ends of the conductors. If the fixation turns out to be weak, it is recommended to choose a different type of solder.

The work is completed by cleaning the soldering iron tip and treating it with inactive flux (if it is tinned). Fluxed tools will help you perform high-quality soldering in the future. It is recommended to store the soldering iron in a closed box.

Popular questions

How should I strip the ends of the wires?

It is not recommended to use coarse abrasives for cleaning. Their particles get stuck in the surface and it is not possible to completely remove them. And during operation, abrasives provoke the development of the oxidation process. High-quality cleaning will be ensured by: scraper, knife, file, needle file. When working with conductive wires, it is recommended to pre-coat them with activated flux, the remains of which should be removed after soldering is completed.

What power should I choose a soldering iron for household needs?

Power determines the function of the tool. If the main part of the work is planned with profiles and thick conductors, then a device up to 65 W is suitable. Soldering of wires with a diameter of up to 0.6 mm is carried out with a soldering iron up to 25 W.

Does the method of twisting play a role in the strength and functionality of the connection?

Each method has its own purpose:

• simple twists are suitable for single-core and stranded wires , but they must first be cleared of the insulating layer;

• bandage connections are used when working with thick live wires;

• grooved ones are made with conductors having fusible insulation;

• simple but consistently performed twisting (British) is used to connect current-carrying cables with a cross-section of up to 1.4 mm2.

How long does it take to heat the solder?

When soldering, some people put solder on a soldering iron. There is no need to do this. It is enough to place the solder over the twisted conductors and warm it up, barely touching the tip. 3-4 seconds are enough for the substance to melt.

By what signs can you understand that soldering has been completed successfully?

The following signs indicate a successful job:

• a layer of solder must cover all ends of the conductors;

• soldering color should be shiny, not matte;

• under mechanical influence (light!) the connection maintains its integrity.

Is there any preparation required for a new soldering iron?

Yes, the tip of a new tool must be cleaned of oxide and coated with tin. After heating, the tip is rubbed against an ammonia stone, after which a drop of solder is melted on it. The preparation of the soldering iron is completed by the usual cleaning of the tip.

Watch the video “How to solder with a soldering iron”


Twist welding machine

When replacing wiring, it is better to weld or solder all twists of copper wires; I have even seen such welding on aluminum wires in the wiring of a house built in 1960. Even then, builders knew about welding wires. Read on to learn how to make a machine for welding copper strands with your own hands.

Wago terminals

Many will probably say: What are Wago-type terminals for? It's the 21st century!

I answer right away: I installed these “super terminals” when replacing the wiring in the apartment, and when I turned on the electric kettle, such a terminal melted, I didn’t like it very much, I even disassembled one such terminal and saw that the contact there was very thin.

Therefore, sometimes the good old twist will be more reliable than all this modern “good”!

At one time, of course, there were good dead-end terminals - you insert a twist into it and tighten it with a screw - it turns out to be insulated and firmly fixed - an awesome thing, but now they have completely disappeared from sale. It's a shame  


Did you like the article? Share with friends:
Metals and their processing
-- Sideb lion (lipk) -->
What is metal galvanization

For any suggestions regarding the site: [email protected]
Для любых предложений по сайту: [email protected]