How to make a magnetic mass for a welding machine. Ground clamp

The electrical circuit of welding equipment carries large currents, so each element of the circuit must be securely connected. This is a matter of quality, ease of use and safety. The most critical link here can be considered the point at which the mass is attached to the metal workpiece. The unit is a quick-detachable contact (welding clamp) and can be structurally made in several variants.

The need to use different modifications of clamps to secure the ground to the part is often determined by the configuration of the metals that you are going to weld. Let's try to figure out why certain weight clamps are good for welding operations.

In nature, there are four main designs of welding clamps:

a terminal in the shape of a crocodile, which received the same name;
connecting the wire with a magnet;
clamp in the form of a clamp;
a grounding terminal called a centralizer.

Upon careful study of the product of this category offered on the market, one can be convinced that many original designs Welding clamps are a modification of the four main ones listed.

Welding "crocodile"

Quick release welding terminal The “crocodile” structurally looks like a clothespin made of metal, in the contact part of which there are ribbed notches on the biting jaws. Due to them, the clamp is firmly attached to the steel workpiece, providing a reliable electrical connection.

The main advantages of products of this type:

Convenient to use when performing surgical procedures welding work, where you constantly need to move the contact from place to place.
Suitable for fixing to parts and structures of any configuration.
They have excellent electrical conductivity.

Disadvantages of the alligator clip:

With frequent use, the spring weakens, which leads to a loss of strength of the mechanical connection.
The metal walls of the clamp are susceptible to burning, which degrades the electrical connection over time.

For welding machines of different power, manufacturers produce terminals designed for current strengths of 500, 400, 300 and 200 amperes. To perform professional welding work, it is recommended to use ground clamps capable of passing a current of at least 400 amperes.

Information to note. The welding “crocodile” cannot be used when working with parts whose contact pad size exceeds the opening size of the clamp jaws (pipes, cylindrical barrels).

Magnetic mass

An electrical clamp, one part of which is made of a metal magnet, and the other is a steel contact with a bolted connection for securing the cable, is called a magnetic mass.

Magnetic clamps have the following advantages:

Have simple design without mechanically moving parts, which significantly increases the service life of such products.
Allows you to fix the mass on any steel surface, regardless of size and configuration.
The electrical connection can be established in a matter of seconds, which is especially important for on-line welding processes.
Possibility of establishing contact in hard-to-reach places.
No tendency to burn out due to unstable electricity flow or voltage sags.

Significant disadvantages of magnetic clamp:

Weak mechanical, and therefore electrical connection with parts whose contact pads are significantly smaller than the contact plane of the magnet.
Inability to make contact through a surface made of non-ferrous metals.
The need to constantly clean the magnet from metal dust, which weakens the electrical connection in the circuit.
Overheating the magnet can lead to demagnetization.

Clamp

It is rare to find a clamp in the arsenal of ordinary welders. Welding clamps of this type can be used by professionals to solve special problems. In particular, when performing precise operations, where you need to get a high-quality, beautiful seam.

The advantages of using a clamp:

Achieving contact with better mechanical fixation by tightening with a screw.
Reliable electrical contact ensuring good throughput welding current, which eliminates the possibility of burning and overheating at the connection point.

Main disadvantages:

The clamp is not suitable for quickly changing the position of the contact on the surface of the part.
As in the case of the “crocodile”, the clamp design can be fixed to elements whose size is comparable to the space between the bolt and the thrust leg.
A clamp is a large product and is more expensive than a regular clothespin.

Information to note. Separate view– corner clamps for welding, which can be used as a ground terminal (with certain modifications); in addition, they will perform a fixing function, rigidly connecting the parts of the frame being welded.

Welding centralizer

A specially designed welding clamp to create mass contact with metal parts such as pipes. Structurally, the centralizer is made of two elements, shaped like the working part of the pliers. The components are connected by a hinge and tightened with a screw. In addition to pipes, the centralizer can be attached to any metal workpiece, as long as its thickness does not exceed the opening capabilities of the terminal jaws.

Advantages of the centralizer:

Hard physical and electrical contact with metal.
Ease of use when performing welding operations with pipes.

Disadvantages of the terminal:

A complex design that does not allow you to quickly switch the welding clamp from place to place.
High price for the product.

What to look for when choosing a welding clamp

You need to start with the purpose for which the terminal is selected, that is, how loaded it will be, what type of machine is used for welding. Professionals take earth clamps for a welding machine with a margin of strength, amateurs - so that they look beautiful (and this happens), but the right approach is based on the following principles:

The clamping power must be designed for a higher current relative to the rated current at which the inverter operates.
Specifics of the welding process: if you need to constantly and quickly change the connection point, then an element like a clothespin is suitable.
The compression force of the tightening jaws should be sufficient to hold the cable if the latter is suspended during the welding process.
The opening size of the terminal jaws must exceed the size of the contact pad where it is planned to connect the ground.
You should pay attention to whether the manufacturer can be trusted. If the latter has proven itself in the market with the best side, feel free to purchase the product.

How to Make an Alligator Clip Last Longer

The alligator clip has several weak points. It has a spring that has a service life. But even when the compression force is not so important and the issue with the spring disappears, the tendency of the “crocodile” remains to burn out at the junction of two moving parts in the hinge area. This happens because the contact with the cable through bolted connection carried out with only one part of the “crocodile”.

During the welding process, you can observe a process where that part of the “crocodile” where the mass is connected may have poor mechanical and, therefore, electrical contact with the part, while the opposite part, on the contrary, has good contact. Then all the current will flow through this element. But here a weak link appears - the hinge; in the area around it there will be unstable conductivity, overheating and melting of the metal.

Anyone who has real experience in solving the problem of how to improve clamp contact welding mass, or questions on this topic, write in the comments!

It often happens that additional devices welding machines become unusable due to high loads or low-quality materials. Such equipment also includes magnetic mass.

This mechanism is a device, the essence of which resembles a clothespin - the magnetic mass is attached to the elements being welded. Unlike a clothespin clamp, it can be easily fixed to absolutely any surface, is more reliable and durable, is highly resistant to voltage surges, and its wide area reliably protects the tool from short circuits.

Disadvantages include poor compatibility with small surfaces of objects being welded, the inability to attach to non-ferrous metals, and the need to regularly clean the magnet from metal debris and shavings.

In general, a magnetic mass is a fairly simple and reliable device that you can even make yourself. The design includes such elements as: magnet and contact. Both of them are connected to each other by a special fastener. The weight of the device depends directly on its overall dimensions. Simplicity of design is the key to reliable and functional operation of the mechanism.

How to make your own magnetic mass?

Process self-made mass is quite simple. Volume necessary tools and materials are minimal. For assembly you will need:

The magnet is the main element that ensures the strength of the fastening. A fairly powerful and compact magnet can be obtained from failed speakers.
Washer - its size should not differ much from the magnet;
A nut with a bolt - they will serve as a clamp for the wire.

The assembly process includes 6 sequential steps:

The washer is being prepared. For convenience, you should stock up on two units, the size of which will correspond to the selected magnet.
The washer, which will be the bottom part of the device, is drilled.
Preparation of the bolt, which involves grinding down its top.
All elements are assembled into a single structure, which is welded and polished.
The magnet is placed on the bolt and secured with a second washer.
A ground cable is attached to the rod, and the entire device is tightened with a nut.

Each master determines the feasibility of independently producing mass for a welding machine for himself. At the present time, there is enough available for the buyer large selection factory devices at reasonable prices.

The list of basic devices required for manual electric arc welding includes the following items: electrode holder; welding cable to holder; return cable; ground terminal (ground clamp).

Quite often these components are not of high quality and require immediate replacement. There are times when the contractor will need a replacement after a short period of use.

Choice of any technical device or adaptation requires careful and careful approach. A correctly selected ground terminal can protect the performer from electric shock and will guarantee a high-quality and reliable connection. To select the optimal welding work clamp, you should pay attention to the following important aspects.

You have to choose well-known and trusted brands, which will help you avoid purchasing counterfeit products. It is very difficult for a person who does not have sufficient experience to distinguish a fake from an original product. Therefore, you need to buy products only from specialized sellers and suppliers.
The ground clamp for the welding machine should be selected taking into account maximum current, which the unit produces.
Also the clamp should confidently withstand the weight of the connected cable.
If the compression mechanism is spring, then its properties should be sufficient for reliable contact with the work product.
Plays one of the main roles opening angle terminals, the value of which should be sufficient for secure attachment to parts various sizes .

Types of ground clamps

Ground clamps for welding machines, depending on the nature of the fixation, can be of several types. Next, we will look at the main types of clamps, as well as their advantages and disadvantages.

1. W welding mass pressure “crocodile”

Most often, performers use a type clamp for grounding "crocodile" ("clothespin"), which is attached directly to the part.

Advantages:

reliability of connection with the surface of the part;
convenience and speed of use;
minimum connection resistance;
the ability to fix parts of various geometric shape, including complex configurations;
high degree of disclosure.

It is also worth highlighting the main flaws:

low, compared to other types, level of strength of some components - spring;
This type of clamp is used only in cases where it is possible to attach directly to the product.

The alligator clip must be selected based on general recommendations. Terminals of this type are available in three main modifications: mass clamp 300A, 200A and 500A. Depending on the model of the welding machine and the current it produces, you need to determine the optimal modification. To carry out work on professional level It is recommended to purchase a 400-500A clamp.

Useful video

2. Magnetic mass for welding

Welders quite often use magnetic ground clamp. This type has a whole spectrum advantages:

possibility to secure a contact on any surface or structure, including pipes;
simplicity of design ensures durability and trouble-free operation;
absence of springs and other mechanisms also promotes long service life;
a ground magnet for welding is able to withstand voltage surges and not burn out;
successfully used in hard-to-reach places;
The large contact area guarantees secure fastening.

Flaws:

Not reliable fastening contact on small parts, for example, fittings;
impossibility of attaching the clamp to the product from colored metals;
a magnet is needed periodically cleanse, in particular from metal shavings;
should Avoid overheating the magnet, otherwise it may demagnetize; Overheating occurs if the terminal is attached to a dirty surface.

3. Clamp

Welding Ground Clamps Type clamp are used less frequently than the two types listed above. This type of terminal also has several advantages:

high degree of fastening reliability, since fixation is carried out using a hex head screw;
good contact with the workpiece ensures a smooth transition of current.

As shortcomings One can highlight the rather complex structure of the mechanism and the relatively large dimensions of the terminal.

4. Centralizer

In rare cases, experts select a centralizer-type clamp, designed for centering and tacking pipes previously located in the desired position. Can also be used to connect welding parts.

Advantages of this type:

ensuring tight contact;
guarantees welding accuracy;
Suitable for pipes of various diameters.

Flaws:

limited scope;
high cost compared to other types of clamps.

Useful video

And another review from an experienced welder, which has some tricks.

Popular models

Let's look at popular welding clamps masses. On the market for sale consumables There is a wide variety of work clamps for welding, both domestic and foreign. Next we will look at the most popular models.

Ground clamp Ergus 300A Pro, manufacturer - Quattro Elementi (Italy). Characteristics: crocodile type; affordable price; high quality; light weight; supports current up to 300A, which is perfect for the home craftsman.

Ground clamp Skrab 27621 300A(in the picture), made in Italy. Is one of the most optimal options for work at home.

Popular grounding terminals are the models Russian manufacturer « Cord". The Moscow company offers clamps with different types mechanism.

For welding work in industrial or production conditions It is recommended to choose a mass clamp of 500A or more.

Elitech 500A mass clamp, made in China.

Do-it-yourself welding compound

For those who want to create a clamp with my own hands To save money, we suggest you read the instructions.

Magnetic mass for welding is, if not the most common, then the most desirable, so the process of its manufacture will be shown below.

The process is simple, you will need a minimum of tools, and the parts can be at hand.

The performer will need: magnet; two washers the size of the magnet can be made from sheet metal; bolt and nut for clamping the welding cable.

The welding mass holder is assembled in several stages:

At the washer, which will serve as a contact, a hole is drilled corresponding to the diameter of the bolt head;
the top of the bolt must be ground down to the thickness of the washer;
then this structure is welded and cleaned; you should get a mushroom-shaped part with a carved stem;
the magnet is placed on the bolt, with a second washer on top;
Lastly, the end of the cable is attached to the threaded rod, and the entire structure is tightened with a nut.

This homemade welding compound will be a good option for saving money and is suitable for home craftsmen. Although there are many critics. What to choose, homemade, cheap or expensive professional tool, choose for yourself.

Often, additional accessories for the welding machine are either of poor quality and break, or may be missing altogether. Magnetic mass for welding is convenient device, allowing it to be secured to the parts to be welded, and good alternative standard clothespins.

What does such a contact consist of? positive qualities he has and how to make it yourself. More on this later in the article.

Magnet or clip

Typically, welding machines are equipped with a ground cable with a clamp-type holder. At first glance, it is convenient; such a device can be securely attached to almost any surface (sheets, rolled metal, etc.).

But there are situations when it is not possible to install such a mass on the workpiece or, even more often, it burns out. A good alternative would be the magnetic contact of the welding cable.

What are its advantages over a standard clothespin clip?

This is an opportunity to attach the contact to almost any surface without much hassle.
The simple design is almost forever in use and will not break, since there are no springs or mechanisms.
Such a mass perfectly withstands voltage surges and loads, as a result of which it does not burn out.
The large contact area ensures reliable closure.

But this type of contact fastening also has its drawbacks. Main disadvantage- this is that the magnetic mass for welding will not be installed well on small parts, for example, a rod or fittings. The second negative property will be the impossibility of attaching to welded parts made of non-ferrous metals: aluminum, copper and others. Also, over time, the magnet will become contaminated with metal shavings and will need to be cleaned periodically.

Without taking into account the last two factors, this is a rather convenient device that you can even make with your own hands at no extra cost.

Magnetic contact design

The device itself consists of two parts.

Contact. This is the point where the ground cable is secured to the holder.
Magnet. Can be of various shapes and sizes.

These two parts are connected to each other by a fastener. The weight of the magnetic mass for welding will depend on its size. For example, a magnetic welding clamp from ESAB weighs about 850 grams.

The main thing in this design is simplicity, which ensures reliable operation and uninterrupted operation.

Self-production

Of course, such welding compound fasteners can simply be purchased. Manufacturers who make welding equipment, they also produce additional devices in the form of fasteners. But this is an unnecessary financial loss; such a contact can be made independently.

Making a magnetic contact for a welding cable with your own hands is quite simple. You will need a minimum of tools, and the parts can be at hand.

What is needed for this:

First, the magnet. This main detail of the entire device, which will ensure secure fastening. Most often you can see homemade products made from magnets from car speakers.
Secondly, two washers according to the size of the magnet. If you use a car speaker, you can weld a bolt onto one of the washers for further assembly.
Thirdly, a bolt and nut for clamping the cable.

The entire system is assembled as follows:

Washers can be made from sheet metal to fit the size of the magnet. If it's a speaker, it usually has round shape. Accordingly, the washers should be the same.
At the bottom (the one that will serve as direct contact) a hole is drilled along the diameter of the bolt head.
The very top of the bolt must be ground down to the thickness of the washer.
Now this structure is welded and cleaned. You should end up with a mushroom-shaped piece with a carved stem.
The magnet is placed on the bolt, and a second washer is placed on top.
Now the end of the ground cable is attached to the threaded rod and the entire structure is tightened with a nut.

This is how an elementary mass is collected from the simplest material for magnetic welding. Its uninterrupted operation will be proof correct assembly. The dimensions of such a contact will depend on the dimensions of the magnet. Factory-made round masses usually have a diameter of about 50-60 millimeters.

For an experienced welder who knows the principle of operation of the mass on a welding machine, making the required fastening will not be difficult. The most primitive contact can be a piece of rod attached to the cable, which is secured to the workpiece with a pair of welding points. But, of course, such a device is very inconvenient to use.

You can also make your own magnetic holder for electrodes. Which also depends on personal preferences in terms of ease of use.

Homemade magnetic terminal good option saving money. Although whether to use such a mount or not is a matter of personal convenience at work. If welding is rarely used (as usual in everyday life), then you can simply get by with a standard clamp.

When purchasing a welding machine, the following accessories are usually included with it:

electrode holder,

welding cable to it;
return cable,
ground terminal.

If the purchased inverter power source (today almost no one uses transformers for welding) is designed for household work, then in most cases all these components require immediate replacement. Especially when it comes to Chinese welding machines, the share of which today in the welding equipment market is about 98%, although managers (unscrupulous sellers) are trying to “sell” them as Italian, Czech, Danish, French and the like.

If replacement does not occur immediately, it will definitely be required after a short period of operation. Usually, the inverter is equipped with a KV-200 electrode holder for free, which costs $3 (imagine the price the manufacturer sells it for), respectively, this is an economical version and they save on the materials used for manufacturing. This applies to live parts, usually made of metal coated with brass or copper, or low-quality plastic. For welding from time to time in everyday life, the KV-200 can serve for a long time, however, under more intense conditions (for example, if you want to cut holes in metal with an electrode) or simply during prolonged welding, it will overheat and literally fall apart. But over time, even with gentle use, the spring that clamps the jaws of the holder weakens and does not hold the electrode firmly; it begins to wobble. This has a negative effect on the stability of the arc and affects the quality welds, but, most importantly, it affects the welder’s nerves.

The cable usually also leaves a lot to be desired: it is short, and galvanized aluminum is used instead of a copper core.

The same applies to the ground terminal. During intensive welding, it will most likely burn out; over time, the spring and, accordingly, the contact weaken. This can also happen due to corrosion. metal jaws, which need to be constantly cleaned to a shine.

How to choose a good mass if the old one has become unusable for some reason or you initially decided not to use it (due to poor quality)?

Choose brands that already have an established positive reputation. In fact, you are not insured against counterfeit products, which non-specialists cannot distinguish from the original ones. Buy from specialized stores with an established reputation.

The weight should be selected taking into account the maximum welding current of your machine and confidently support the weight of the connected welding cable. If a spring is used as the main “compressive body” in the mass, its spring properties must be sufficient to provide the force necessary to achieve reliable contact with the product. The key role is played by the opening size of the terminal, which should be sufficient for reliable fastening to products of various sizes (including large ones).

Based on design features and the nature of fixation, grounding terminals are divided into several types:

Clamp
Clothespin clip
Magnetic terminal

Each has its own advantages and disadvantages. The clamp guarantees reliable “iron” contact, because it is fixed rigidly with a screw. “Clothespin” is most widespread due to its quick fixation even on products of complex geometric shapes. It is most convenient to use magnetic mass where the previous two do not work: for example, when welding large-diameter pipes.

Depending on the nature of the work ahead, choose which mass design will be optimal for you.

Recommendations for the selection and operation of a “Clothespin” (or “Crocodile”) type ground terminal

As already mentioned, most often in everyday life they use a mass clamp, which looks similar to an ordinary household clothespin for fixing laundry, only many times enlarged. Therefore, we will talk about it in detail in the final part of our article.

Such a mass often fails due to incorrect operation. Knowing how a clothespin works will help extend its life. Please note that on any “clothespin” there is a copper, copper-plated or brass bus that transmits electrical contact from the first clamping jaw to the second. The connected metal of the product you plan to weld should not touch the busbar. Constant contact with the tire will damage it. Options for correct and incorrect connection are shown in the photo.

Wrong

Right

The spring allows you to fix the “clothespin” on the product. However, a problem often arises when the contact that fits with a wire to one clamping jaw slips through the spring to the other. The spring begins to heat up and loses its hardness and rigidity, as a result, the springing properties weaken - the ground terminal becomes completely inoperable.

If you want to buy a good “clothespin” for welding, buy one designed for professional work with a reserve of 400...500A. Which design features have similar products:

Powerful spring capable of providing truly reliable contact;
A large degree of disclosure is sometimes very helpful;
The copper busbar in such “clothespins” is placed in such a way that physical-electrical contact with it is impossible.

Reading time: 2 minutes

Magnetic terminal, magnetic clamp, magnetic contact of the welding cable... This device has many names. But the essence is always the same: a magnet allows you to quickly and reliably attach it to the ground and start welding.

But what is it? What are the pros and cons of a magnetic ground terminal? How to use it and is it worth buying at all? You will find the answer to these and some other questions in our article.

The magnetic contact of a welding cable is a device that is mounted on the surface to be welded (ground) using an active magnetic field. The device is necessary to form a closed electrical circuit. Without this, manual arc welding is impossible.

The magnetic ground clamp is very popular among both beginners and professional welders. Magnetic mass is also often used for DIY welding at home. It quickly and securely attaches to any surface, even curved ones.

Advantages and disadvantages

We have already mentioned several advantages of a magnetic terminal above. But the list does not end there. The magnetic terminal has a simple design, so it is extremely durable and lasts for many years. Simply put, it is a regular magnet with a switchable or permanent magnetic field. There are no springs or anything else mechanical elements which may fail.

The magnetic terminal tolerates temperature and voltage changes well. It rarely burns out and can work with most types of metals. Also, such a ground clamp is indispensable when welding in hard to reach place. Even if the part is bent, the magnet will still provide reliable fastening due to its large contact area.

But it was not without its drawbacks. So the magnetic terminal is not able to provide reliable fastening to small parts. For example, on fittings. To maintain the active magnetic field, the device must be constantly cleaned. Its operation is very badly affected by metal shavings.

Also, to use a magnet, preliminary preparation is required. If you attach a magnet to uncleaned metal, the device will stop working.

Don't forget that there are metals that are not magnetic. These are most non-ferrous metals. You won't be able to use a magnetic terminal with them.

How to use?

There is nothing complicated about using a magnetic terminal. Most models have a special handle, turning which you turn on the magnetic field. By default, the magnet will not attach to metal.

The device must be attached to the part, holding it with one hand. With your other hand, turn the handle, activating the magnetic field. Everything is ready! The magnet holds securely on the metal. To remove the device, simply turn the handle in the opposite direction. There is no need to put any effort into tearing the magnet off the metal.

Is it worth buying?

The answer to this question depends on the specifics of your welding work. You must evaluate for yourself which metals you cook most often and under what conditions. If you are a beginner and do not weld non-ferrous metals, then a magnetic terminal will simplify your work. The same applies to professional craftsmen. But they most likely have a whole set of different terminals for welding any metals.

The magnetic terminal is not cheap (compared to other types of clamps), but it is worth it. If you want to save money, you can make such a terminal yourself. Below is a video that shows how to make a magnetic mass for welding on your own.