Do-it-yourself ground clamp and welding holder. Ground clamp

The electrical circuit of welding equipment carries large currents, so each element of the circuit must be securely connected. This is a question 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 what purpose the terminal is selected for, that is, how loaded it will be, what type of machine is used for welding. Professionals use mass clamps for welding machine with a margin of safety, amateurs - to 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 the ground is planned to be connected.
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!

Ground terminals

Ground terminal(or, otherwise, ground clamp) - a key device for welding: electric arc or semi-automatic. Grounding terminals come in several types. Their characteristics differ depending on the parameters of the welding itself.

What type ground terminals Under what conditions is it more convenient? What characteristics does the choice of this device depend on?

GROUND CLAMP: ROLE IN WELDING

Ground clamp- a device made of various metals that provides connection, on the one hand, to the power source and, on the other hand, to the part being welded.

Regardless of whether it is electric arc welding or semi-automatic, a grounding terminal is needed to ensure that a potential difference is ensured in the welding area.

The terminal must be connected to the power source - into one of the welding sockets on the power source panel.

Which socket should the terminal be connected to, and which should the cable going to the electrode be connected to, depends on a number of parameters. For example, on the type of electrode (for manual arc welding) or on what the power source is - a rectifier or transformer. In the latter case, it does not matter which of the two corresponding sockets is connected to.

Ground clamp then attached to the part being welded or to metal surface, with which the part comes into contact or on which it is located. Thus, the part being welded ends up with a potential of one polarity, and the electrode supplied to it ends up with a potential of the other polarity.

SIGNIFICANT CHARACTERISTICS OF THE TERMINAL

There are several defining characteristics for ground terminals, which you should pay attention to when choosing a device. This:

Clamping force.
opening width.
withstand current.

Clamping force- this is how tightly the terminal is attached to the part. If it is not strong enough, it may not support the weight of the welding cable and the welding connection will break.

Opening width(for clamp-type terminals, see below) is measured in millimeters and shows how thick a plate the terminal can hook onto.

Withstand current- a characteristic that is of primary importance for welding work. What current the terminal can withstand, we can carry out welding work at this current. You need to clearly know for what welding work the grounding terminal is purchased so as not to make a mistake with the amount of current the terminal can withstand.

WHAT DOES TERMINALS DAMAGE?

Ground clamp may overheat. The cable insulation melts, the cable burns out, and the surface on which the terminal is attached oxidizes. As a result, the contact between the terminal (and therefore the current supplied through the cable) and the surface (part) deteriorates.

What causes this?

First of all, due to the fact that the place where the terminal is attached may be covered in paint or dirty.
Also, due to insufficient contact of the cable with the terminal - at the attachment point.
The third reason is the poor quality of the terminal itself. If the terminal is made of iron and coated with copper, then the copper layer can wear out, burn out and thus become insufficient.
Another reason for terminal damage is due to the lack of a protective busbar (made of copper) in the terminal. The bus connects the ends of the terminal jaws. If any of the two jaws (in crocodile type terminals, see below) has unreliable contact with the surface, current flows through the bus. But if there is no bus, then the current can flow through the center of the terminal, where the spring is located, and the terminal will deteriorate.

WHAT ARE THERE?

The following common types of ground clamps are available:

clamp terminals("crocodile" type) - are used where it is possible to grab the surface plate (if this is not possible, sometimes a rod is specially welded to which the terminal is attached).
magnetic - used in hard-to-reach places or where it is not possible to grab the plate with a clamp terminal (for example, when working with pipes).

Peculiarity magnetic clamps is that it is necessary to avoid overheating them, because the clamp is demagnetized. Overheating in in this case often happens where the magnetic terminal is attached to a heavily contaminated surface and the contact is insufficient.

SUMMARY

The grounding terminal should be selected based on:

Firstly, from its mechanical characteristics (how wide the alligator clip opens, how tight the clamp provides).
secondly, from the current required for welding work, which is indicated in the characteristics of the terminal.

If the terminal is magnetic, pay attention to the absence of dirt and other foreign objects in the contact area between the clamp and the surface.

If ground terminal together with the corresponding connected welding cable is included in the kit - then there are no questions with the choice of terminal. However, if you choose a mass clamp for any special type of welding work (“assemble.” welding equipment for the required welding process), then the current carried by the terminal should be paid attention first.

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Magnetic terminal, magnet 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 an 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.

As a rule, the welding machine is equipped with a cheap grounding terminal. But its quality is such that in most cases it quickly fails or is not suitable for the welder for some other reason. You need to go to the store to buy a new terminal.

How to choose from the offered range if you are just starting to weld? What do you need to know for this? Read in the article.

Due to poor contact, the welding process will be constantly interrupted. Therefore, the mass clamp must be selected based on the following considerations:

Taking into account the maximum operating current of the welding machine;
It must support the weight of the connected cable;
The spring compression force must ensure reliable contact with the product or the copper pad on which it is installed;
The opening size of the terminal should guarantee reliable fastening on structures of small and large sizes.

Ground terminals come in three types:

clamp;
clothespin "Crocodile";
magnetic clip.

If a situation arises during your work in which it is difficult to grasp with a clamp or crocodile, you can easily do this using a magnetic clamp. With a magnet, you can easily attach to any surface, be it a pipe or a structure of complex shape.

Home design feature Such welding mass is a spring, which ensures quick fastening to the metal. It is also the “Achilles heel” of the device.

Understanding the operating principle of a crocodile-type mass allows you to extend its life and not ruin it after two or three welding jobs. What are we talking about? On any clamp there is a strip (copper-plated or brass) that transfers contact from one clamping jaw to another. If you do not monitor its condition and incorrectly connect the mass to the metal, it may deteriorate. A common malfunction is that a contact that fits with a wire to one clamping jaw may slip through the spring to another. As a result, the spring begins to heat up, which leads to a loss of its hardness and spring properties (in metallurgy this process is called tempering), aimed at reliable fastening of the clamp to the surface metal product. Because of this, the mass is destroyed at a rapid pace. To maintain working condition, you need to monitor the condition of the strip: it should not touch the metal when connecting. The photos clearly demonstrate what is meant.

Correct contact

Buy a "crocodile" for professional work. Which positive aspects it usually has:

the design is correct (the strip is recessed so that it cannot be touched)
quality materials,
more powerful spring;
larger girth (sometimes it is simply not replaceable).

Take with a reserve of 400 -500A.

How to improve the ground terminal?

What are the dangers of steel jaws? They will get hot - steel is a much worse conductor than copper or brass. To prevent this from happening, you can remake a cheap clothespin that costs 40-50 rubles. (if, of course, you have some copper or brass in your household, for example, a plate or tube, a busbar).

What needs to be done? You need to unscrew the original jaws, which are held on by bolts, and use them, like a template, to make other jaws. It is enough that in cross-section they represent the Russian letter “P”. Without special effort you will get a good contact on a poor quality clothespin!

Do-it-yourself magnetic clamp for welding

Welders can appreciate the benefits of using a magnetic terminal when working with complex structures, where a regular “crocodile” simply has nowhere to hook. And here you throw the mass onto the surface of the metal being processed - and you perform welding work.

You can buy it at any welding supply store, but will it meet your needs and be as reliable as a terminal you make yourself? Everyone comes up with something, some make “crocodiles” in the garage, but magnetic masses few people undertake to invent... In general, do it and you will have something to brag about to your welding friends!

The terminal itself is cut from 2mm and 0.5mm sheet metal, and the magnet is taken from a non-working speaker, and a 20x20x3mm hot-rolled angle segment is also used here as a cable pressure plate. All other components: screws, washers, nuts are standard.
The connection can be made to the ground cable of the welding machine, replacing the standard “crocodile”, or you can separately equip this type of ground with a bayonet connector and a cable with a cross-section of 1x16mm.

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, the 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 of 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: ground 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:

unreliable contact fastening on small-area 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 inability to attach 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 produce welding equipment also produce additional devices in the form of fasteners. But this is an extra 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.