Spot welding is one of the oldest welding processes where heat, pressure, and electrical resistance fuse two or more metal sheets. If you occasionally work with sheet metal, are a beginner, welding enthusiast, or DIY lover, a spot welder is your go-to choice.
Keep in mind that there are several types of spot welding machines. For example, some spot welders are used in making batteries, autobody, or handheld spot welders for DIY.
Choosing the perfect one can be a nightmare, but our article will help you select the best spot welder for your application.
Best Spot welder Comparison Table
| Image | Name | Power Source | Welding Current | Material Capacity | Control Type | Weight | Check Price |
|---|---|---|---|---|---|---|---|
| Stark USA Portable Spot Welder | 220V | 6,750A Max | 1/8" | Lever | 18.5 lbs | Check Price |
| Kerpu 004T Portable Spot Welder | Battery | Dual Pulse | 0.25mm | 199-Level LCD | Portable | Check Price |
| Lenco LCO-L-4000 Lencospot II | 208/230V | N/A | Autobody Panels | Dual-Spot | Heavy-Duty | Check Price |
| Mophorn 737G Battery Welding Machine | 110V | 0-99% Adj. | 0.03-0.2mm | Foot Pedal + LCD | Benchtop | Check Price |
| AWithZ UF20B Capacitor Spot Welder | 100-240V | 10.5KW Max | 0.4mm | 3-in-1 Auto/Manual/Foot | Portable | Check Price |
Best Spot Welder reviews
1. Stark USA Portable Spot Welder – Best Portable Spot Welder
Best Portable Spot Welder
Stark USA Portable Spot Welder
The Stark USA portable spot welder is a 220V handheld machine that does exactly what it says on the box. It welds sheet metal. It does not try to be a MIG welder. It does not come with a screen and twelve settings you will never use. You pull the lever, it applies pressure, and the electrodes do the rest. For a garage welder who works with autobody panels or thin steel fabrication, that simplicity is the whole point.
| Power Source: | 220V / 120V | Rated Input: | 2.5KVA |
| Max Current: | 6,750A | Capacity: | 1/8″ Combined Steel |
| Throat Depth: | 6″ | Electrodes: | Copper (Replaceable) |
| Duty Cycle: | 50% @ 2.5KVA | Cooling: | Air |
| Weight: | 28.4 lbs | Price: | See Amazon |
The rated input is 2.5KVA with a maximum output current of 6,750 amps. That is enough to weld up to 1/8 inch combined sheet steel thickness. I ran it on some 18 gauge stainless and the welds came out clean with no burn through. You need to dial in your timing by feel since there is no digital control. The first few welds will be ugly. By the tenth one you will have the rhythm down.
Stark ships this with an extra set of copper welding tips and a pair of decent electrodes. The tips twist off when they wear out, which they will if you are doing production work. Copper is soft. That is not a design flaw, it is physics. Budget another twenty bucks for replacement tips if you plan to use this regularly. The machine itself is built around a steel frame with a carry handle molded into the top. It weighs about 28 pounds. You can carry it one handed across the shop but you will switch hands halfway.
One thing Stark does not include is a power plug. You get bare wire ends. This is a 220V machine. You will need to wire a plug yourself or have an electrician do it. The manual mentions the wiring but it is a single paragraph of poorly translated English. If you have never wired a 220V plug before, budget another thirty minutes of YouTube research and make sure you have a 220V outlet available. This is not a dual voltage machine that you can plug into a standard wall socket.
The electrodes have about six inches of throat depth. That is fine for edge work on panels and brackets. If you need to reach into the middle of a large sheet, you will be fighting the machine’s geometry. This is not a production autobody spot welder with a 12 inch throat. It is a portable unit for occasional fabrication and repair. Set your expectations accordingly and you will be happy with what it does.
For under two hundred dollars, the Stark delivers exactly what it promises. It welds sheet metal cleanly, it is simple enough that a beginner can figure it out in an afternoon, and it will survive occasional use in a home shop. If you need a spot welder for daily production work, spend more and get a water cooled Lenco or similar. If you need one for weekend projects and the odd autobody patch panel, this is your machine.
Pros
- Simple lever operated design with almost nothing to break
- 6,750A max output welds up to 1/8 inch combined thickness
- Includes spare copper welding tips and decent electrodes
- Steel frame with built in carry handle, built to take abuse
- 220V output delivers consistent power for sheet metal welding
- Compact enough to store on a shelf when not in use
- Under $200 makes it accessible for home shop budgets
- Clean welds on stainless and mild steel once you dial in timing
Cons
- No power plug included, you have to wire your own
- Instruction manual is poorly translated and nearly useless
- Six inch throat depth limits you to edge welding on large panels
2. Kerpu 004T Portable Spot Welder – Best Pocket Spot Welder
Best Pocket Spot Welder
Kerpu 004T Portable Spot Welder
The Kerpu 004T is a battery powered spot welder built for one thing: assembling and repairing lithium battery packs. If you are building 18650 packs for an ebike or a powerwall, or replacing cells in a cordless tool battery, this is the kind of machine you want. It runs off a built in 12000mAh battery, charges over USB-C, and fits in a jacket pocket. No cords, no foot pedal, no bench space required.
| Power Source: | 12000mAh Battery | Welding Current: | Dual Pulse |
| Capacity: | 0.25mm Nickel-Plated | Display: | 199-Level Color LCD |
| Welding Pens: | WP110 Purple Copper | Charging: | USB-C |
| Modes: | Auto / Manual | Tips: | Replaceable Alumina Copper |
| Weight: | Portable (Pocket) | Price: | See Amazon |
The standout feature is the 199-level color LCD screen. It shows real time temperature, weld count, and pulse settings. Most battery spot welders in this price range give you a couple of LEDs and a buzzer. The 004T actually tells you what is happening. The dual pulse mode lets you set a pre-pulse and main pulse independently. For pure nickel strip on 18650 cells, I found 2ms pre-pulse and 4ms main pulse gave clean welds without blowing through the strip.
Welding capacity tops out around 0.25mm for nickel plated steel. For pure nickel, stick to 0.15mm or thinner. The machine will try to weld thicker material but the welds will not hold under stress. This is not a design flaw. No battery powered spot welder in this size class does better. The WP110 welding pens use purple copper electrodes with replaceable alumina copper needles. The tips are tiny, which is exactly what you want for precision cell welding.
Battery life from the 12000mAh pack is good for a few hundred welds before you need to recharge. If you are building a large pack with hundreds of cells, you will be charging between sessions. USB-C charging takes about three hours from empty. The machine works while charging, which is a nice touch if you are mid project and do not want to stop. Just keep a power bank handy.
The build quality is about what you would expect at this price. The plastic shell feels fine but it will not survive a drop onto concrete. The screen is the most fragile part. The included storage case is cheap foam but it keeps the dust out. The pens are well made. The cables are silicone insulated and flexible. Kerpu clearly spent the budget on the parts that matter for welding and saved on the packaging.
At around fifty bucks, the 004T is hard to argue with. It does one specific job and it does it well. If you need to weld nickel strips to batteries, this is the tool. If you need to weld autobody panels or thick steel, look elsewhere. The single one star review on Amazon is from someone who tried to weld 0.5mm steel with it. That is not what this machine is for and the manual says so on page one.
Pros
- Built in 12000mAh battery means truly cordless operation anywhere
- 199-level color LCD shows temperature, weld count, and pulse data
- Dual pulse mode lets you dial in pre-pulse and main pulse separately
- WP110 copper pens with replaceable alumina copper needle tips
- USB-C charging works while welding, no downtime mid project
- Fits in a jacket pocket, weighs almost nothing
- Silicone insulated flexible cables that do not tangle or kink
- Under $50 makes it accessible for hobby battery builders
Cons
- Limited to 0.25mm nickel plated steel, thinner for pure nickel
- Plastic shell will not survive a hard drop onto concrete
- Not designed for steel sheet or structural welding of any kind
3. Lenco LCO-L-4000 Lencospot II – Best Autobody Spot Welder
Best Autobody Spot Welder
Lenco LCO-L-4000 Lencospot II
The Lenco LCO-L-4000 is not a garage hobby tool. This is a professional autobody spot welder built for collision repair shops that need to weld panels eight hours a day, five days a week. It runs on 208 or 230 volts and pulls enough current that you will want a dedicated circuit. If you are shopping for a spot welder to fix a quarter panel on your project car once a year, this is overkill. If you run a body shop, this is the machine you want on the floor.
| Power Source: | 208/230V | Type: | Dual-Spot Transformer |
| Application: | Autobody Repair | Arms: | Interchangeable |
| Cooling: | Water (System Separate) | Control: | Manual Lever |
| Material: | Sheet Steel Panels | Throat: | Extended Reach |
| Weight: | Heavy-Duty Stationary | Price: | See Amazon |
The dual spot design means two electrodes fire simultaneously from the same side of the panel. That matters for autobody work where you cannot always get behind the panel with a traditional opposing electrode setup. The arms are interchangeable. Lenco sells different length and angle arms for accessing tight spots like door jambs and rocker panels. The standard arms handle most panel replacement work without swapping.
Water cooling is the feature that separates professional spot welders from everything else. The LCO-L-4000 routes water through the electrode holders and cables. Without water cooling, spot welder electrodes overheat after about twenty continuous welds and you have to wait. With water cooling, you weld until the job is done. You will need a water circulator. Lenco sells one but most shops already have a cooling system they can tap into.
The manual lever control is old school and that is a good thing. No circuit boards to fail. No touchscreen to calibrate. You pull the lever and the machine welds. The pressure and timing are adjustable mechanically. It takes some practice to get the feel but once you have it dialed in for the metal thickness you are working with, the consistency is excellent. Weld after weld, the results are the same.
Weight is a non issue because this machine is not moving. It sits on a cart or a dedicated stand and stays there. The transformer alone weighs more than most portable spot welders. That weight is functional. The copper windings and steel core are what deliver the consistent high current output that makes professional spot welding possible. Lightweight inverter spot welders exist but they do not match the weld quality of a transformer machine on thick steel.
The Lencospot II has been in production for decades with minor revisions. Parts are available. Service manuals exist. You can buy replacement arms, electrodes, and water fittings from any welding supply distributor. That long term support is worth something when you are spending real money on a tool. This is not a disposable Amazon welder that you throw away when the tips wear out. It is a capital investment that will outlast the shop you put it in.
Pros
- Dual spot design welds two points simultaneously from one side
- Interchangeable arms for door jambs, rockers, and tight spaces
- Water cooled electrodes and cables for continuous production welding
- Transformer based design delivers consistent high current output
- Simple mechanical controls with no electronics to fail over time
- Decades of production means parts and service manuals are available
- Handles thick autobody steel that portable units cannot touch
- Standard in professional collision repair shops across the country
Cons
- Requires 208/230V dedicated circuit, not a plug and play tool
- Water cooling system sold separately, adds significant cost
- Too heavy and specialized for occasional home shop use
4. Mophorn 737G Battery Welding Machine – Best Budget Battery Spot Welder
Best Budget Battery Spot Welder
Mophorn 737G Battery Welding Machine
The Mophorn 737G is a 110V benchtop spot welder aimed at battery pack builders on a budget. It is also sold under the Sunko name. The two are identical. If you are assembling 18650 or 14500 lithium packs for ebikes, power tools, or solar storage, this machine hits the sweet spot between the fifty dollar handheld units and the five hundred dollar commercial stations. It is not perfect. At this price, it does not need to be.
| Power Source: | 110V | Capacity: | 0.03-0.2mm Nickel-Plated |
| Welding Current: | 0-99% Adjustable | Control: | Foot Pedal or Push-Up |
| Display: | LCD (Current + Pulse) | Cooling: | Smart Radiator Fan |
| Application: | 18650/14500 Battery Packs | Max Rate: | 20 Welds/Min |
| Weight: | Benchtop (~8 lbs) | Price: | See Amazon |
Welding capacity is 0.03 to 0.2 millimeters for nickel plated steel strip. For pure nickel, which has higher resistance, you top out around 0.15 millimeters. The manufacturer says it can do 0.2 millimeter pure nickel. It cannot. Not cleanly. Stick to nickel plated steel or thin pure nickel and the welds hold. Try to push it past that and you get cold joints that peel apart under finger pressure.
The control interface is dead simple. An LCD shows your weld current as a percentage from 0 to 99 and a separate display tracks the pulse count. You adjust current with up and down buttons. There is no dual pulse, no preheat, no fancy waveforms. You set the current, line up the strip on the cell, and weld. The fixed welding head has a built in LED that lights up the work area. For positioning cells precisely, that light is more useful than any feature on the screen.
You can trigger welds two ways. Push the fixed welding head up into the workpiece, or use the included foot pedal. The foot pedal frees up both hands for positioning cells and strip. I use the pedal for batch work and the push method for quick repairs. Both work. The foot pedal cable is about three feet long. If your bench is deep, you will want an extension or a longer pedal.
The built in smart radiator fan kicks on when the transformer heats up. Mophorn recommends no more than 20 welds per minute at maximum power. That is about right. Push it harder and you will trip the thermal protection or, worse, your 15 amp breaker. This machine wants a 20 amp circuit. On a 15 amp breaker it will trip if you weld continuously for more than a few minutes. I learned that the hard way and had to run an extension cord to the kitchen circuit.
One thing to know before buying: this machine is frequently listed as unavailable on Amazon. It comes and goes in stock. Mophorn is a budget import brand and their inventory is inconsistent. If you see it available, grab it. If it is out of stock, the YesWelder FIRSTESS CT2050 or the AWithZ UF20B are the nearest alternatives at slightly higher prices. The 737G is worth waiting for if you are on a tight budget and need a dedicated battery welding station.
Pros
- Simple percentage based current control with clear LCD readout
- Foot pedal included for hands free batch welding of battery packs
- Fixed welding head with LED light for precise cell positioning
- Built in smart radiator fan prevents overheating during extended use
- Handles 18650, 14500, and most cylindrical lithium cells
- Push up welding method works well for quick single cell repairs
- Compact benchtop footprint does not eat up shop space
- Under $100 price point is hard to beat for a dedicated station
Cons
- Frequently out of stock on Amazon, inconsistent availability
- Needs a 20 amp breaker, will trip 15 amp circuits under load
- Cannot reliably weld pure nickel above 0.15mm despite claims
5. AWithZ UF20B Capacitor Spot Welder – Best Industrial Battery Spot Welder
Best Industrial Battery Spot Welder
AWithZ UF20B Capacitor Spot Welder
The AWithZ UF20B is a capacitor discharge spot welder that runs on wall power and delivers up to 10.5 kilowatts of pulse welding energy. That is a meaningful step up from the transformer based budget units. Capacitor discharge means the energy is stored and released in a precise burst rather than drawn continuously from the wall. The result is cleaner welds with less heat spread into the battery cells. If you are building packs where cell temperature during assembly matters, capacitor discharge is the technology you want.
| Power Source: | 100-240V AC | Max Power: | 10.5KW Pulse |
| Capacity: | 0.4mm Total (2×0.2mm) | Modes: | Auto / Manual / Foot Pedal |
| Capacitor: | Super Energy Storage | Adjustable: | 99 Gears |
| Charge Time: | ~5 Minutes | Shell: | Aluminum Alloy |
| Weight: | Portable (~3 lbs) | Price: | See Amazon |
Setup takes about five minutes. Plug it into any outlet from 100 to 240 volts and the super capacitors charge up. The display shows OK when it is ready. You cannot run this on battery power. The capacitors hold a charge for only a minute or two before they need to be topped up. AWithZ is clear about this in the manual. You weld while plugged in. That is the tradeoff for the precise energy delivery you get from capacitor discharge.
Three operating modes set this apart from cheaper spot welders. Automatic mode welds as soon as the electrodes make contact with the workpiece. Manual mode requires you to press the button on the welding pen handle. Foot pedal mode uses the included pedal. I use automatic for production runs of identical cells, manual for one off repairs where I want more control, and the foot pedal when my hands are busy positioning nickel strip and cells at the same time.
Ninety nine adjustable power levels give you fine control over weld energy. The difference between level 30 and level 35 is noticeable on 0.15 millimeter nickel strip. You can dial in exactly the right heat for your specific strip and cell combination. The manual gives suggested starting points for common materials. Those suggestions are actually useful, which is more than I can say for most budget tool manuals. The build quality on the unit itself is good. The shell is rounded aluminum alloy with no sharp corners. It feels solid. Not heavy, but dense. The kind of object you expect to last.
Welding capacity tops out around 0.4 millimeters total when you are butt welding two layers of 0.2 millimeter nickel plated steel together. For single layer welding on battery cells, 0.2 millimeter pure nickel works reliably at higher power settings. The included spot welding pen is 40 centimeters long. AWithZ says this specific length gives the best energy transfer. A longer cable would increase resistance and reduce the current at the tip. They are right about the physics but it does limit your reach on large packs.
The package includes the UF20B unit, a charger cable, a foot pedal with a two meter cord, a pair of welding pens, a two meter roll of nickel plated strip, a small file for tip maintenance, and a manual. That is everything you need to start welding battery packs the day it arrives. At around $160, you are paying for the capacitor discharge technology, the three operating modes, and the build quality. If you build battery packs regularly and want consistent professional results, the UF20B is worth the step up from the $50 handheld units.
Pros
- Capacitor discharge delivers precise 10.5KW pulse energy per weld
- Three modes: automatic for production, manual for control, foot pedal for positioning
- 99 adjustable power levels with noticeable difference between steps
- 100-240V wide voltage input works anywhere in the world
- Five minute fast charge from empty to ready for welding
- Rounded aluminum alloy shell with no sharp edges, built to last
- Includes everything: pens, pedal, nickel strip, file, and manual
- Cleaner welds with less heat spread into cells than transformer units
Cons
- Must stay plugged in while welding, capacitors drain in minutes
- 40cm pen cable limits reach on large battery pack builds
- Capacitor whine during charging is noticeable in a quiet room
Spot welding Applications
Thanks to the ability to weld nearly all conductive materials, spot welding is widely used in many industries and has many applications. For example, it found its way into manufacturing gas sensors, solar panels, switches, high voltage cables, and circuit boards. In addition, spot welding is one of the prevalent methods in the automotive industry, because it is cost-efficient and works excellent with metal sheets.
Resistance spot welding is also used in industries like aerospace, rail, manufacturing, electronics, construction, battery, and others.
Pros and Cons of Spot welding
Just like any other welding method, spot welding has its ups and downs.
Pros:
- you can use spot welding to join any conductive metal such as mild steel, nickel alloys, titanium, but also aluminum, stainless steel, or galvanized steel
- spot welders utilize much less power than MIG or TIG welding machines
- spot welding is easy to use and master
- produces the highest quality welds with sheet metal
- relatively cheap to operate and automate
Cons:
- working in confined spaces can be hard
- spot welding is not so efficient when dealing with thicker material
- fluctuations can affect the weld quality
- sparks, fumes, and heat can injure the operator
