Spot welding machines: how to choose best models
To choose the right spot welding machine, you need to understand the capabilities and key parameters of the equipment.
In addition, it is useful to read the welders ‘ reviews of specific models.
All this is in our review, which will help you choose the equipment that will cope with the upcoming tasks.
- The principle of spot welding
- Advantages of spot welding
- How to choose a spot welding machine
- Types of spot welding machines
- Exposure modes
- Operating mode
- Maximum welding current
- The maximum thickness of the welded sheets
- Connection voltage
- Management method
- Additional parameters
- The best spot welding machines
- SVA caliber-1.5 AK
- Fox weld KTR-8 3097
- FUBAG TS 2600 38 666
- RedHotDot HAMMER IT 275116
- Fox Weld MTR-25 3373
WIEDER KRAFT WDK-6000
The selection of products is based on the reviews, opinions, and ratings of users posted on various resources on the Internet.
All information is taken from open sources.
We do not cooperate with manufacturers and brands and do not encourage the purchase of certain products.
The article is informational in nature.
The principle of spot welding
First, let’s look at the device and the principle of operation of spot welding machines.
The equipment is connected to a 220 or 380 V network and converts alternating current to direct current.
For this purpose, inverter technology is used.
The step-down transformer inside reduces the number of volts to 12-48 and increases the amperage.
A cable is attached to the power source, at the end of which a gun or console with an electrode is attached.
The latter belongs to the non-consumable type (usually an alloy of copper with chromium).
It should be several times thicker than the cross-section of the metal being welded.
A brief touch of the end of the electrode to the product produces spot heating, which melts the iron.
The metal molecules are mixed to form a single crystal lattice.
A point connection is obtained. If you break it, then on one side there will be a depression (crater), and on the other side, there will be a core.
Since the contact is made by an electrode with a small cross-section, the surrounding surface is heated less and does not deform.
In this way, you can connect sheet blanks, wire, or weld rods to a plane (panhandles, etc.).
Advantages of spot welding
With its help, the end of the reverse hammer is welded to the damaged places, with which the dents are pulled out.
This type of welding is also used in the manufacture of metal utensils, various fences.
Among the advantages of spot welding, the following parameters can be distinguished:
- Neat and precise seams.
- Reduce the cost of electricity and consumables (no melting electrode, no gas needed, as in a semi-automatic).
- High performance.
- Highly qualified personnel are not required (it is enough to show you how to use it a couple of times and let you practice on the rough details).
- When working with a product thickness of 0.5-1.0 mm, there are no burns.
- There is no need for subsequent mechanical processing of the joints.
How to choose a spot welding machine?
To understand how to choose spot welding, you need to remember the seven main parameters that you should pay attention to before buying.
There are also additional factors that play a role only in certain operating conditions.
All equipment capable of performing spot welding is divided into two categories: portable and stationary.
The first type is characterized by compact dimensions within 30x20x30 cm and weighs up to 16 kg. Such models are able to weld metal with a cross-section of 1.5+1.5 mm.
The maximum indicator can reach 5 mm. Portable products are relevant for body repairs or the production of large metal structures (doors, gates, racks).
The device can be carried around the product and perform welding.
Portable spot welding machine.
Stationary spot welding machines are used in production facilities.
With their help, they perform the assembly of products that the operator can hold in his hands.
The same type of connections is created very quickly during mass production, which contributes to increased productivity.
But such installations take up a lot of space due to the dimensions of 50x60x100 cm and can weigh up to 100 kg. A powerful current source allows welding metal with a total thickness of up to 8 mm.
Stationary spot welding machine.
Spot welding machines can work on workpieces using one of two methods.
Single-sided spot welding
One-way mode is implemented in models called spotters.
They are equipped with a pistol with a rod and a reverse hammer, at the end of which there is a copper electrode in the form of a triangular star.
Holding the electric welding to the surface, you can make reverse strikes, pulling the dented metal.
Spotter for single-sided spot welding.
One-way exposure mode is justified in the case of difficult access to the reverse side of the structure (you need to remove the door trim, dismantle the car wing), or when the product is too large.
In this way, you can also weld a washer or comb to the surface to act simultaneously on a large area, pulling all the elements at once with the help of hooks.
Spotter for single-sided spot welding working principle
Working as a spotter for single-sided spot welding.
Double-sided spot welding
Double-sided welding is used for joining sheet metal overlap.
To do this, the devices are equipped with tongs that wrap around the product.
The maximum distance of the connection point from the edge of the structure depends on the departure of the consoles.
This parameter can be from 12 to 50 cm. In such devices, the lower console is stationary, and the upper one is lowered, simultaneously pressing and warming up.
double-sided spot welding machine
Pliers for double-sided spot welding.
The operating mode of the device is soft and hard, which depends on the characteristics of the current.
In the first case, a low current density is used, but the welding cycle is performed with an extended duration of 2-5 seconds. This allows the use of electrodes with a smaller cross-section (it can be equal to the thickness of the workpiece) and not too much pressure with tongs.
In the second case, a current of higher density is used, and the cycle lasts shorter — 0.2-1.5 s. This model provides increased speed of operation but requires strong compression of the workpieces and the diameter of the electrode, several times larger than the total cross-section of the welded parts.
Maximum welding current
The maximum welding current depends on the capabilities of the spot welding equipment.
A value of 3000 A will allow you to connect parts with a total cross-section of up to 3 mm. Machines with an index of 6000 A can weld steel up to 4-5 mm. Industrial machines 10000-16000 A allow you to connect workpieces up to 9 mm (in total).
The maximum thickness of the welded sheets
An important parameter that shows what the maximum cross-section of the device is able to boil.
If you ignore this value and use the equipment on thicker parts, the quality of the connection is reduced.
The parameter can be specified in general, for example, “5 mm”, or divided into two parts — “2.5+2.5 mm”, which will mean the same thing.
There are industrial versions that are able to weld three sheets of steel together at once. Then it is denoted as “3+3+3 mm.”
To connect the device to the mains, a single-phase voltage of 220 V or a three-phase line of 380 V.
This is directly indicated in the instructions for the product and determines where it will be used.
The power consumption from 3 to 12 kW will tell you whether it is possible to include the device in a normal household network (usually more than 5 kW is better not to include, so as not to melt the wiring).
The cheapest devices are controlled manually.
In some models, it is not even possible to set the current strength — it always works at the maximum.
The operator himself squeezes the pliers with his hands and monitors the time of contact of the electrodes to form the desired weld.
For a high-quality connection, you first need to test the device on rough blanks with the same thickness as the main product.
After determining how much time is needed for clamping, you can proceed to weld.
There are devices with current adjustment, which slightly simplify the work with metals of different thicknesses.
The microprocessor (synergistic) control makes the work much easier.
The welder indicates on the panel the type of connection to be made (welding of the washer, wire, lap welding, etc.), as well as the thickness of the product.
The synergetic control automatically selects the optimal parameters for welding, supplies current, and disconnects it.
The operator can only bring the electrodes and put them in the right place. But such models are much more expensive.
Microprocessor-controlled spot welding machine
If the long-term operation of the device is required, then pay attention to the type of cooling.
Devices with a water system and a radiator remove heat faster and have a longer service life.
The spotter will definitely need a pistol and a reverse hammer.
To perform welding, use copper electrodes, which are consumable elements.
For mobile devices with a weight of 13 kg or more, it is practical to purchase a trolley to transport them on wheels.
The best spot welding machines
If you need contact spot welding for a home workshop or small production, then pay attention to the following models, which have already been tested by customers and received positive feedback.
This is the best device in terms of cost and power of the prow.
Users in the reviews share that they easily weld 2+2 mm sheet metal together, performing 15 points per minute.
If you need to connect the wire, the model will cope with the cross-section of the bars of 5+5 mm.
But the connection needs a powerful network, so for a garage, such spot welding is not worth choosing.
Fox weld KTR-8 3097
In second place in the rating is a product from the Italian brand Foxweld.
The spot welding equipment has two copper brackets, a clamping handle, and a bump plate.
The power of the current source is 8 kW and the device is able to cook with 6000 A.
The manufacturer claims that the inverter will easily connect two workpieces with a cross-section of 1.5+1.5 mm.
The model belongs to the professional class and has IP21 housing protection.
Advantages of Fox weld KTR-8 3097
- Large handle for lifting the device.
- Relatively small dimensions 41x10x23 cm.
- The extension of the electrodes of 15 cm allows you to start large parts between them.
- The increased power of the welding current.
Disadvantages of Fox weld KTR-8 3097
- There is a slight backlash, which is why the electrodes do not exactly converge with each other.
- You need good wiring from 4 mm2.
- It is difficult to move often due to the weight of 14 kg.
- The power is not regulated.
Judging by the reviews, this device for performing spot welding is used by most users for the manufacture of metal doors.
Welders say that this is much more convenient than operating a semi-automatic machine and after welding, no additional cleaning of the seams is required.
FUBAG TS 2600 38 666
And here is a spot welding machine called a spotter.
It is designed to perform one-sided tacks on metal with a cross-section of up to 1.5 mm. The maximum current is 2800 A.
The dimensions of the equipment are 20x32x18 cm.
When connected to a single-phase network, the device consumes 5.4 kW, so it can be used in the garage or in the country.
The kit comes with a pistol and a rod with a reverse hammer.
There are three “star” electrodes and one carbon electrode for heating the metal surface.
Advantages of FUBAG TS 2600 38 666
- Switch for welding with carbon and copper electrodes.
- Light indication of overheating and network availability.
- Four modes of operation.
- Creates a reliable connection.
Disadvantages FUBAG TS 2600 38 666
- A large weight of 14 kg is inconvenient to move often.
- High cost.
- There is no amperage current adjustment (only according to the welding method).
This model is designed for car body repair and is able to work in several modes: welding of corrugated wire, rings, heating the surface with a carbon electrode, tack “stars”.
Pay attention to the powerful reverse hammer on the gun. The weight of the weight is 1.1 kg, which ensures fast pulling of dents.
RedHotDot HAMMER IT 275116
The Hummer brand is produced in Italy.
The model IT 275116 produces a maximum current of 3200 A.
This allows you to weld sheet metal with a cross-section of 1.5+1.5 mm. Connecting to a single-phase 220 V network and power consumption of 3 kW does not overload the household wiring, so you can use the device even in the garage.
The digital display is convenient for visual control of the entered parameters.
The indicator indicates that the overload is triggered. Included with the spotter is a pistol with replaceable nozzles.
Pros of RedHotDot HAMMER IT 275116
- Housing protection
- Do not create an excessive load on the network due to the power of 3 kW.
- Small dimensions 30x18x26 cm.
- Deep penetration and strong connection.
Cons of RedHotDot HAMMER IT 275116
- High cost.
- It weighs more than 16 kg.
- To some welders, the reverse hammer design seems weak.
The spot welding model is notable for its synergistic control, where the welder selects one of six modes, depending on the configuration of the element to be welded.
The thickness of the metal is set on the digital display. The microprocessor itself selects the optimal parameters for performing the existing task.
Fox Weld MTR-25 3373
Next in the rating is a spot welding machine, which is designed for operation inside the production shop.
The device needs to be connected to a three-phase network at 380 V.
The control is mechanical, and the compression of the pliers is carried out by a foot drive.
The welder’s hands can support the workpiece at this time. The power of the equipment is 25 kW.
The case has dimensions of 87x40x121 cm and weighs 100 kg.
Advantages of Fox Weld MTR-25 3373
- Easy operation.
- Long service life.
- It doesn’t break down during everyday work.
- Start squeezing the pliers with the pedal-your hands are always free.
Cons of Fox Weld MTR-25 3373
- Very high cost.
- The weight of 100 kg requires a reliable base under the machine.
- Users do not have enough tables under the pliers to turn over the workpieces.
- It is necessary to sharpen the electrodes frequently during heavy use.
We recommend this machine for performing serial spot welding in production.
The model has a welding current of 16000 A and is able to weld workpieces with a thickness of 2.5+2.5 mm.
One point is made in 10 seconds, which allows you to put 6 stitches per minute at once.
Another feature of the product is water cooling in a system with a radiator. It removes excess heat and extends the time of continuous operation.
WIEDER KRAFT WDK-6000
The spotter on the cart completes our review. It contains a spot welding gun and a reverse hammer.
The model produces a maximum current of 4400 A. The body is protected according to the IP23 standard, so you can work with the device outside when it rains (finish leveling the body part and remove it to the room).
The input power is 11 kW. The welding time can be adjusted from 1 to 10 seconds. The welder does not need to monitor this — the machine turns off the welding current itself. Potholders are strong and without burns.
Advantages of WIEDER KRAFT WDK-6000
- Can be connected to 220 V.
- Increased reliability.
- Eight modes of welding.
- Digital display and synergistic control.
Cons of WIEDER KRAFT WDK-6000
- High cost.
- There is no cooling fan.
- It is necessary to provide a place for the device with dimensions of 60x50x95 cm.
This spotter for spot welding is notable for its performance on a trolley. In this case, the power supply is located on the top, so you do not need to bend down to enter the settings.
At the bottom, there is enough space for cables, consumables, and tools. The cart is equipped with wheels, where the two front wheels rotate 360 degrees to the sides.
This makes it easy to move quickly around the shop floor and is great for the auto repair shop to restore the body geometry while moving around the machine.
What kind of spot welding machine did you decide to buy?
- SVA caliber-1.5 AK
- Fox weld KTR-8 3097
- FUBAG TS 2600 38 666
- RedHotDot HAMMER IT 275116
- FoxWeld MTR-25 3373
- WIEDER KRAFT WDK-6000