How to choose from the proposed range if you are just starting to weld? What do you need to know for this? Read 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 compression force of the spring must ensure reliable contact with the product or the copper lining on which it is installed;
- the size of the terminal opening must guarantee a secure fastening on structures of small and large sizes.
Ground terminals are of several three types:
- clamp;
- clothespin "Crocodile";
- magnetic clamp.
If a situation arises in the work in which it is problematic to grab a clamp or a crocodile, you can easily do this with a magnetic clamp. With a magnet, you can easily fix on any surface, be it a pipe or a structure of complex shape.
The main design feature of such a welding mass is a spring, which ensures quick fastening to the metal. It is also the “Achilles heel” of the device.
Understanding the principle of work of the mass of the "crocodile" type allows you to extend its life and not ruin it after two or three welding jobs. What is this about. Any clamp has 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 fault: a contact that fits with a wire to one clamping jaw can slip through the spring to another. As a result, the spring begins to heat up, which leads to the loss of its hardness and spring properties (in metallurgy, this process is called tempering), aimed at reliable fastening of the clamp on the surface of the metal product. Because of this, the mass is destroyed at a rapid pace. To maintain a healthy state, you need to monitor the condition of the strip: it should not touch the metal when connected. The photos clearly show what is meant.
Correct contact
Get a "crocodile" for professional work. What are the 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 margin of 400 -500A.
How to improve the ground terminal?
What are the dangers of steel sponges? They will heat up - steel is a much worse conductor than copper or brass. To prevent this from happening, you can remake a cheap clothespin worth 40-50 rubles. (unless, of course, you have some copper or brass on your farm, for example, a plate or tube, a tire).
What should be done? It is necessary to unscrew the native sponges that are held on by bolts, and use them, as if according to a template, to make other sponges. It is enough that in cross section they represent the Russian letter "P". Without much effort, you will get good contact on a poor-quality clothespin!
Magnetic terminal for DIY welding
Welders can appreciate the advantage of using a magnetic terminal when working with complex structures, where there is simply nowhere to hook an ordinary “crocodile”. And here he threw the mass on the surface of the metal being processed - and you perform welding work.
You can buy it at any welding supply store, but will it fit your needs and be as reliable as a terminal made by yourself? Everyone somehow invents, some make “crocodiles” in the garage, but few people undertake to invent magnetic masses ... In general, do it and there will be something to brag to your friends - welders!
- The terminal itself is cut out of 2mm and 0.5mm sheet metal, and the magnet is taken from a non-working speaker, and a segment of a hot-rolled corner 20x20x3mm is also used here as a cable pressure plate. All other components: screws, washers, nuts are standard.
- The connection can be made to the cable of the mass of the welding machine, replacing the standard "crocodile", or you can separately complete this type of mass with a bayonet connector and a cable with a section of 1x16mm.
Ground terminals
Ground terminal(or otherwise, ground clamp) - a key device for welding: electric arc or semi-automatic. Ground 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? On what characteristics does the choice of this device depend?
GROUND CLAMP: ROLE IN WELDING
Mass clamp- a device made of various metals, which provides a connection, on the one hand, to the power source and, on the other hand, to the workpiece to be welded.
Regardless of whether it is electric arc welding or semi-automatic, the ground terminal is needed so that a potential difference is provided in the welding zone.
The terminal must be connected to the power source - to one of the welding sockets on the power source panel.
To which socket the terminal should be connected, and to which - the cable going to the electrode 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 a transformer. In the latter case, it does not matter which of the two corresponding sockets is connected.
Mass clamp further attached to the welded part or to the metal surface with which the part is in contact or on which it is located. Thus, the workpiece to be welded is with the potential of one polarity, and the electrode supplied to it is with the potential of the other polarity.
ESSENTIAL CHARACTERISTICS OF THE TERMINAL
There are several defining characteristics for ground terminals which should be taken into account when choosing a device. This is:
Clamping force.
opening width.
withstand current.
clamping force is how strongly the terminal is attached to the part. If 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 indicates how thick a plate the terminal can hook on.
Withstand current- a characteristic that is of paramount importance for welding work. What current the terminal can withstand, we can carry out welding work of such a current. It is necessary to clearly know for which welding work the ground terminal is purchased, so as not to be mistaken with the value of the current withstand by the terminal.
WHAT DOES THE TERMINALS BE DAMAGED
Mass clamp may overheat. The cable insulation melts, the cable burns out, the surface on which the terminal is attached is oxidized. As a result, the contact between the terminal (and hence 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 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 damage to the terminals is due to the lack of a protective busbar (made of copper) in the terminal. The bus connects the ends of the jaws of the terminal. If any of the two sponges (in the “.crocodile” type terminals, see below) has unreliable contact with the surface, the current passes through the bus. But if there is no bus - then the current can go through the center of the terminal, where the spring is located, and the terminal will deteriorate.
WHAT ARE
There are the following common types of ground clamps:
pincer terminals(like "crocodile") - are used where it is possible to grab onto the surface plate (if this is not possible, sometimes a bar 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 clamping terminal (for example, when working with pipes).
Peculiarity magnetic clamps in that it is necessary to avoid overheating them, because the clamp is demagnetized. Overheating in this case often occurs where the magnetic terminal is attached to a heavily contaminated surface and the contact is insufficient.
SUMMER
The ground terminal should be selected based on:
Firstly, from its mechanical characteristics (how wide the crocodile-type terminal opens, how tight the clamp provides).
secondly, from the current necessary for welding, 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 area of contact between the clamp and the surface.
If a ground terminal together with the appropriate connectable welding cable is included in the kit - then there are no questions with the choice of the terminal. However, if you choose a ground clamp for any special type of welding (“. assemble.” welding equipment for the necessary welding process), then the current that the terminal can withstand should be paid attention first of all.
The electrical circuit of the welding equipment passes large currents, so each element of the circuit must be securely connected. It is a matter of quality, usability and safety. The most responsible link here can be considered the point of attachment of the mass to the metal workpiece. The assembly is a quick-detachable contact (welding clamp) and can be designed in several versions.
The need to use different modifications of clamps to fix the earth to the part is often due to the configuration of the metals that you are going to weld. Let's try to figure out how good these or other mass clamps are for performing welding operations.
In nature, there are four main designs of clamps for welding:
- a terminal in the form of a crocodile, which received the same name;
- connecting the wire with a magnet;
- clamp in the form of a clamp;
- ground terminal, called a centralizer.
A close examination of the goods in this category offered on the market, you can see that many of the original designs of welding clamps are a modification of the four main ones listed.
Welding "crocodile"
The quick-detachable welding terminal "crocodile" structurally looks like a clothespin made of metal, in the contact part of which there are ribbed notches on the biting lips. Due to them, the clamp is firmly attached to the steel workpiece, making a reliable electrical connection.
The main advantages of products of this type:
- Convenient to use when performing operational welding, where you constantly need to rearrange the contact from place to place.
- Suitable for fixing on parts and structures of any configuration.
- They have excellent electrical conductivity.
Disadvantages of the crocodile clip:
- With frequent use, the spring is weakened, which leads to a loss of strength of the mechanical connection.
- The walls of the metal of the clamp are subject to burn-out, which degrades the electrical connection over time.
For welding machines of different power, manufacturers produce terminals designed for a current of 500, 400, 300 and 200 amperes. For professional level welding, it is recommended to use ground clamps with the ability to pass a current of at least 400 amperes.
Note information. Welding "crocodile" cannot be used when working with parts, the size of the contact pads of which exceeds the opening size of the jaws of the clamp (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 attaching a cable, is called a magnetic mass.
Magnetic clamps have the following advantages:
- They have a 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 seconds, which is especially important in on-line welding processes.
- Possibility of establishing contact in hard-to-reach places.
- The absence of a tendency to burn out with an unstable flow of electricity, voltage drops.
Significant disadvantages of the magnetic clamp:
- Weak mechanical, and hence electrical connection with parts, the size of the contact pads of which is much smaller than the contact plane of the magnet.
- Inability to make contact through a surface made of non-ferrous metals.
- The need for constant cleaning of the magnet from metal dust, which weakens the electrical connection in the circuit.
- Overheating the magnet can cause it to demagnetize.
Clamp
It is rare to find a clamp in the arsenal of ordinary welders. Welding clamps of this type can be used by professionals for special tasks. In particular, when performing precise operations, where you need to get a high-quality beautiful seam.
Benefits of using clamps:
- Obtaining a contact with a better mechanical fixation due to tightening with a screw.
- Reliable electrical contact, providing a good throughput of the 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 design of the clamp can be fixed to the elements, the size of which is comparable to the space between the bolt and the thrust foot.
- The clamp is a large-sized product and is more expensive than a regular clothespin.
Note information. A separate view is 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 to be welded.
Welding centralizer
Specially designed welding clamp to create ground contact with metal parts such as pipes. Structurally, the centralizer is made of two elements, shaped like the working part of the tongs. The components are connected by means of a hinge and pulled together by a screw. In addition to pipes, the centralizer can be attached to any metal workpiece, as long as its thickness does not exceed the possibility of opening the jaws of the terminal.
Benefits of the centralizer:
- Rigid physical and electrical contact with metal.
- Convenience of work when performing welding operations with pipes.
Terminal disadvantages:
- A complex design that does not allow you to quickly switch the welding clamp from place to place.
- The high price of the product.
What to look for when choosing a clamp for welding
You need to start with the purpose for which the terminal is selected, that is, how much it will be loaded, what type of apparatus is used for welding. Professionals take mass clamps for a welding machine with a margin of safety, amateurs - to look beautiful (and this happens), but the correct approach is based on the following principles:
- The clamping power must be designed for a higher current than the rated current on which the inverter operates.
- The specifics of the welding process: if you need to constantly and quickly change the connection point, then a clothespin type element will do.
- The compression force of the tightening jaws should be enough to hold the cable if the latter is suspended during the welding process.
- The size of the opening of the jaws of the terminal must exceed the size of the contact area where it is planned to connect the mass.
- You should pay attention to whether the manufacturer can be trusted. If the latter has proven itself in the market from the best side, feel free to purchase the product.
How to make your crocodile clip last longer
The crocodile clip has several vulnerabilities. It has a spring that has a service time. But even when the compression force is not so important and the issue with the spring disappears, there is a tendency for the "crocodile" to burn out at the junction of two moving parts in the hinge area. This is because the contact with the cable through the bolted connection is made with only one part of the "crocodile".
During the welding process, one can observe a process when that part of the “crocodile” where the mass is connected can have poor mechanical, and therefore electrical contact with the part, while the opposite part, on the contrary, is good. Then all the current will go through this element. But here a weak link appears - a hinge, in the area of it there will be unstable conductivity, overheating and penetration of the metal.
Anyone who has real experience in solving the problem, how to improve the contact of the clamp of the welding mass, or questions on this topic, write in the comments!
It often happens that additional devices of welding machines, to the extent of high loads or low-quality materials, become unusable. 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 to be welded. Unlike a clothespin clip, it can be fixed to absolutely any surface without any problems, it is more reliable and durable, it is highly resistant to voltage surges, and its wide area reliably protects the tool from short circuits.
Among the shortcomings, one can single out poor compatibility with small surfaces of objects to be welded, the impossibility of attaching to non-ferrous metals, as well as the need for regular cleaning of the magnet from metal debris and chips.
In general, the magnetic mass is a fairly simple and reliable device, which can even be made independently. The design includes such elements as: magnet and contact. Both of them are interconnected by a special mount. The mass of the device depends directly on its overall dimensions. The simplicity of the design is the key to reliable and functional operation of the mechanism.
How to make your own magnetic mass?
The process of self-manufacturing mass is quite simple. The amount of necessary tools and materials is minimal. For assembly you will need:
- The magnet is the main element that ensures the strength of the fastening. A sufficiently powerful and compact magnet can be obtained from failed speakers.
- Washer - its size should not differ much from the magnet;
- Nut with a bolt - it is they who will carry the function of the wire clamp.
The assembly process includes 6 successive stages:
- The puck 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 of the device, is drilled.
- Preparation of the bolt, which involves grinding off its top.
- All elements are assembled into a single structure, which is subjected to welding and grinding.
- The magnet is put on the bolt and fixed with a second washer.
- A mass cable is attached to the stem, and the entire device is tightened with a nut.
The feasibility of self-manufacturing mass for the welding machine, each master determines for himself. At the present time, a fairly large selection of factory devices at affordable prices is presented to the buyer.
The list of basic devices necessary for manual arc welding includes the following items: electrode holder; welding cable to the holder; return cable; ground terminal (ground terminal).
Quite often, these components are not of high quality and require immediate replacement. There are times when a contractor will need a replacement after a short operation.
The choice of any technical device or fixture requires a careful and careful approach. A properly selected ground terminal will be able to protect the performer from electric shock, and will become a guarantee of obtaining a high-quality and reliable connection. To select the optimal welding mass clamp, you should pay attention to the following important aspects.
- Gotta choose well-known and trusted brands which will help to avoid the purchase of 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 goods only from specialized sellers and suppliers.
- The ground clamp for the welding machine should be selected taking into account maximum current The that the aggregate emits.
- Also, the clamp must confidently support the weight of the connected cable.
- If the compressive mechanism is spring, then its properties should be sufficient for reliable contact with the working product.
- Plays one of the main roles opening angle terminal, the value of which must be Sufficient for secure fastening to parts of various sizes.
Ground clamp types
Mass clamps for welding machines, depending on the nature of fixation, can be of several types. Next, we will look at the main types of clamps, as well as their advantages and disadvantages.
1. Z Welding weight press "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 shapes, including those with a complex configuration;
- high degree of disclosure.
It should also highlight the main limitations:
- low, in comparison with other types, the 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 crocodile 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 strength that it produces, it is necessary to determine the optimal modification. For work at a professional level, it is recommended to purchase a clamp for 400-500A.
Useful video
2. Magnetic mass for welding
Welders often use magnetic ground clamp. This type has a wide range virtues: 
- opportunity to make contact on any surface or structure, including pipes;
- simplicity of design ensures durability and trouble-free operation;
- lack of springs and other mechanisms also contributes to long-term operation;
- a ground magnet for welding is able to withstand voltage drops and not burn out;
- successfully used in hard-to-reach places;
- a large contact area guarantees secure fastening.
Disadvantages:
- unreliable fastening of the contact on small parts, for example, fittings;
- the impossibility of fixing the clamp on the product from colored metals;
- a magnet is needed periodically decontaminate, in particular from metal shavings;
- should avoid overheating the magnet, otherwise it may become demagnetized; overheating occurs if the terminal is attached to a dirty surface.
3. Clamp
Ground clamps for welding type clamp are used less frequently than the two types listed above. This type of terminal also has several virtues:
- high degree of fastening reliability, since fixation is carried out using a hexagonal screw;
- good contact with the workpiece ensures a smooth current transition.
As shortcomings one can distinguish a rather complex structure of the mechanism and the relatively large dimensions of the terminal.
4. Centralizer
In rare cases, specialists single out a centralizer-type clamp designed for centering and tacking pipes pre-located in the desired position. It can also be used to connect welding parts.
Advantages of this type:
- ensuring tight contact;
- guarantees welding accuracy;
- suitable for pipes of various diameters.
disadvantages:
- limited scope;
- high cost compared to other types of clamps.
Useful video
And another reviewer from an experienced welder, which has some tricks.
Popular Models
Consider the popular mass welding clamps. On the market for the sale of consumables for welding, there is a wide variety of mass clamps, both domestic and foreign. Next, we will consider the most popular models.
Mass clamp Ergus 300A Profi, manufacturer - Quattro Elementi (Italy). Characteristics: type "crocodile"; affordable price; high quality; light weight; supports current up to 300A, which is perfect for a home master.
Mass clamp Skrab 27621 300A(on the picture), production - Italy. It is one of the best options for working at home.
Popular ground terminals are models from a Russian manufacturer " Cord". The Moscow company offers clamps with various types of mechanism.
For welding work in industrial or production conditions, it is recommended to choose a ground clamp of 500A or more.
Mass clamp Elitech 500A, made in China.
Do-it-yourself mass for welding
For those who want to create a clip with their own hands and save money, we suggest that 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 need a minimum of tools, and the parts can be at hand.
The contractor will need: magnet; two washers according to the size of the magnet can be made from sheet metal; bolt and nut for clamping the welding cable.
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 part in the form of a mushroom with a threaded leg;
- the magnet is put on the bolt, on top - the second washer;
- lastly, the end of the cable is attached to the threaded rod, the entire structure is tightened with a nut.
Such a home-made mass for welding will be a good cost-saving option and is suitable for home craftsmen. Although there are many critics. What to choose, a homemade product, a cheap product or an expensive professional tool, choose for yourself.
Often, accessories for a welding machine are either of poor quality and break, or may be absent altogether. The Magnetic Welding Compound is a handy tool for attaching to the parts to be welded and a good alternative to standard clothespins.
What does such a contact consist of, what positive qualities does it have and how to make it yourself. More on this later in the article.
Magnet or clip
Typically, welding machines are equipped with a mass cable with a clamp-type holder. At first glance, it is convenient, such a device can be securely fixed 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, 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 fix the contact on almost any surface without much hassle.
- The simple design is almost eternal in use, it will not break, as there are no springs and mechanisms.
- Such a mass perfectly withstands voltage drops and loads, as a result of which it does not burn out.
- The large contact area ensures reliable closing.
But there are also disadvantages to this type of fastening of contacts. The main disadvantage is that the magnetic mass for welding will be poorly installed on parts that are small in area, for example, a bar or reinforcement. The second negative property will be the impossibility of fastening to welded parts made of non-ferrous metals: aluminum, copper and others. Also, over time, the magnet will become contaminated with metal shavings and needs to be cleaned periodically.
Without taking into account the last two factors, this is a rather convenient device that you can even make yourself at no extra cost.
Magnetic contact design
The device itself consists of two parts. 
- Contact. This is the point where the ground cable is attached to the holder.
- Magnet. It 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 have depending on the dimensions. For example, an ESAB magnetic welding terminal weighs about 850 grams.
The main thing in this design is simplicity, due to which reliable operation and uninterrupted operation are ensured.
Self-manufacturing
Of course, such fasteners of the welding mass can simply be purchased. Manufacturers that manufacture welding equipment also produce accessories in the form of fasteners. But these are unnecessary financial losses, 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, a magnet. This is the main part of the entire device, which will ensure the reliability of fastening. Most often you can see homemade products made from a magnet from car speakers.
- Secondly, two washers according to the size of the magnet. If you use a car speaker, then a bolt can be welded onto one of the washers for further assembly.
- Thirdly, a bolt and nut for clamping the cable.
The assembly of the entire system is carried out in this way:
- Washers can be made from sheet metal, according to the size of the magnet. If this is a speaker, then it usually has a round shape. Accordingly, the washers should be the same.
- At the bottom (the one that will serve directly as a 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 get a part in the form of a mushroom with a threaded leg.
- The magnet is put on the bolt, and on top - the second washer.
- Now, the end of the mass cable is attached to the threaded rod and the entire structure is tightened with a nut.
So, from the simplest material, an elementary mass is collected for welding on a magnet. Its smooth operation will be proof of proper assembly. The dimensions of such a contact will depend on the dimensions of the magnet. Prefabricated round masses usually have a diameter of about 50-60 millimeters.
For an experienced welder who knows the principle of the work of the mass on the welding machine, it will not be difficult to make the required fastening. The most primitive contact can be a piece of rod fixed to the cable, which is fixed 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. That also already depends on personal preferences in the convenience of work.
A homemade magnet terminal is a good option to save money. Although to use such a mount or not - this is already looking at personal convenience at work. If welding is rarely used (as usual in everyday life), then you can simply get by with a standard clamp.