Welding Ground Magnet, Types, How to Use (Video), and Choose

By Ben Norton / May 18, 2019
Welding Ground Magnet Title Image

What is A Welding Ground Magnet?

A welding ground magnet, also known as a welding magnetic ground clamp or referred to as a magnetic ground for welding is essentially a magnet.

Yes, that does sound obvious but wait …

For those of us who weld it is a useful addition that is added to our welder for welding.

Specifically it is a magnet can be added to a MIG, TIG, stick or flux core only welder to replace the existing metal ground clamp.

Instead of having a toothed metal clamp at the end of your welder’s grounding cord, you connect this magnet. The magnetic attraction allows it to stick to mild carbon steel and low carbon steel, grounding the metal you’re welding.

Types of Magnetic Ground in Welding

There are two main types of magnetic grounds for welding.

One type is called a rare earth magnet. And as its name suggests it is made from the alloys of rare earth elements. This type of grounding magnet is a permanent, strong magnet.

The other type is called an electromagnet. Electrical force creates the magnetic field.

Welding Magnetic Ground Clamp Welding Vertically

Welding Magnetic Ground Clamp Welding Vertically

Why Use a Magnet For your Welding Ground?

Because they are quick and convenient to attach and use.

I’ll suggest some example situations.

You are welding up a repair on your car or truck, let’s say the roof. It’s a large expanse of metal and it is difficult to clamp your existing ground close to where you’re welding.

Or your welding on a curved surface, repairing a pipe or some steel tubing. Your normal clamp can’t open wide enough to clamp around the curved metal surface.

Maybe you are welding around sensitive material or equipment and you need to get your welding ground as close to the weld as possible.

In any of these situations you could weld on a tab of metal and attach your normal ground clamp to that. But when you’re done you have to remove the tab and grind and tidy up the area you attached it to.

With a welding magnetic ground clamp you attach it to your project, its magnetic attraction keeps it there and you weld.

Like I say;

Quick and convenient.

What Metals Can You Use a Welding Ground Magnet On?

Ferrous metals like mild steel or low carbon steel. These metals are magnetic and so a magnetic ground clamp can attach to them.

If all your welding work is done on mild steel or low carbon steel then a magnetic ground for welding could save you a ton of time when using your welder.

As long as the metal is clean, just stick it on close to where you need to weld and your ready to go.

How to Use a Magnetic Ground in Welding

Whether you have the rare earth or the electromagnetic type you remove your existing metal ground clamp. Put the new magnetic clamp on the end of the ground cord from your welder.

YouTube Video Of a Welding Magnetic Ground Clamp

Want to see a welding ground magnet in action?

This short 1 minute 23 second video shows you what a welding ground magnet looks like, how it attaches and how easy it is to use.

Electrical Grounding Clamp 300 Amp – Magswitch Technology


Video Credit: Magswitch Technology

Best Practices For Positioning your Welding Magnetic Ground Clamp

It is better to set up your magnetic ground a few inches away from your welding torch. Or if stick welding several inches away from your electrode. Why?

1. Because the heat from your weld puddle travels along the steel. High heat and magnets don’t mix well. Heat can demagnetize your magnet causing it to fall off and then you have no ground. Place at least a couple of inches away from your weld puddle.

2. Another reason for the spacing is a magnetic ground clamp too close to your weld puddle will pull the molten metal to one side. This will distort your weld pool and weld. The distortion happens because the molten metal pulls towards the magnetic field of the clamp.

If you really have to have the clamp close to the pool then I suggest you position the magnet welding clamp in the direction you plan to weld in.

3. To weld steel your welder needs certain polarity sittings. This is true whether you are MIG or flux core welding or stick welding with a flux core electrode.
Polarity is a magnetic force. And you need the polarity flowing in the right direction for you to get a good weld. Position your magnet a minimum of a couple of inches away so that it doesn’t interfere with your welding polarity.

4. If you use welding angle magnets to position your steel take care as you weld toward them.

Angle magnets are magnets. And the last thing you need is magnetic fields competing. You’ll experience problems with your welding arc or even striking your arc.

And potentially arc strikes (scoring of your metal by electrical arcing) where you put your magnetic ground for welding. I tell you more about arc strikes below.

5. Keep your welding ground magnet away from any equipment close to where you are welding, that might be susceptible to strong magnetic fields. Some examples to think about are: On a car or truck – away from the alternator, car alarm, any sensors or the radio.

6. Your magnetic ground clamp just like your metal one needs a good connection. And just because it sticks well does not mean the connection is clean enough for your welder. It’s not enough for the magnet to hold.

Avoid placing your ground magnet on paint or rust. Grind down to some good clean steel near where you’re welding for the best connection. The attachment point just like for a traditional ground clamp needs to be clean.

Welding Magnetic Ground Clamp Vertically Attached

Welding Magnetic Ground Clamp Vertically Attached

What is Arc Strike Or Arc Burn On Your Steel?

Should the magnetic ground fall off the steel, be kicked or vibrate off while you are welding, you loose your ground. As your ground connection fails the electricity passing through your magnet can arc. This leaves arc strike and burn marks on your steel.

It is unsightly and the scoring of the metal will need a fix and tidy up. But more important is that arc strikes can weaken the mild steel at the place of the strike.

When is it Best to Use a Welding Ground Magnet – Advantages

  1. When what you’re welding – its size, shape or its position makes hooking on a standard ground clamp difficult.
  2. When your metal clamp dies. For example, the ground cable breaks from your normal clamp. What do you do? Attaching a magnetic ground is an option.
  3. When the look of the piece or size of the part you are welding is important. Welding a tab so you have a place to put your clamp isn’t desirable. Cause then you will have to cut it off and grind out the spot later.
  4. To ground your welding table. It is an advantage yes. But watch for placing the ground too far away from your project piece and causing a poor arc.
Welding Ground Magnet Attached to Welding Table

Welding Ground Magnet Attached to Welding Table

When Not To use A Welding Magnetic Ground Clamp – Disadvantages

  1. Doesn’t work on Aluminum or stainless steel. Mainly weld those metals? Then one of these is not for you.
  2. The small metal pieces produced by welding – shards from any rust, grinding, spatter or cutting – are attracted to the magnet. On a permanent rare earth magnet these shards are a devil to get off. Choose a ground welding ground magnet you can switch off. Then those shards drop easily off.
Ground Magnet for Welding Turn The Knob To Turn On

Ground Magnet for Welding Turn The Knob To Turn On

Features to Look For When Choosing Your Magnetic Ground for Welding

1. Amperage

Magnetic grounds for welding are sized by the maximum amperage they support. And similar to the welding machines they attach to, they all have duty cycles.

Always find out the maximum amperage of the magnetic ground clamp and its duty cycle. Compare to the maximum amperage of your welder and its duty cycle.

Go for an amp rating on the welding ground magnet well above the minimum you need.

Have a 140 Amp welder with a 20% duty cycle? Then as a minimum you will need a 200 Amp magnetic ground with a 50% duty cycle.

2. Check the User Experience

You’ll want your magnetic clamp to grip well. A magnetic clamp falling off part way through your weld is guaranteed to get annoying real quick.

3. Pounds of Magnetic Power

Welding ground magnets state the lbs. of weight their magnetic field will support. You want to try and get the most powerful magnet you can for your budget.

Bear in mind that the magnet needs to support the weight of your ground cable. If you occasionally fix to a vertical surface you’ll have the weight of gravity working against you. Pulling the magnet down and away.

Plus you may accidentally tug or bump the grounding cable or magnetic clamp while you are welding. All of which could send it pinging off onto the floor. Unless you have a powerful magnet.

4. Size and its importance

The best magnets are a small enough to be convenient to stick anywhere. This means that you can get into the tightest spots and not have to expose too much bare metal for your magnetic welding clamp to fix to. You want a small but powerful foot print.

5. Permanent versus Electromagnetic Welding Ground Clamps

Check whether the ground clamp you are choosing is a rare earth magnet that is always on. They collect metal debris and are not so easy to work with and a pain to keep clean.

Metal Shards Attached to the Magnetic Ground Clamp

Metal Shards Attached to the Magnetic Ground Clamp

Magnetic clamps with a handle or lever that allows you to release it quickly and disconnect the clamp are preferred. As are magnets you can turn off to clean.

Some magnetic clamps have spring loaded studs in the middle, levers or a ceramic pot in the middle. Those tend not to fix so well.

Finding the Best Welding Ground Magnet

I’ve selected three I consider the best and I give you my reasons why. You can use the links I have provided to head over to Amazon or in the case of the Welding Grasshopper to Sawyer Manufacturing.

Take a look and see if you like the look of them and feel they can do the job for you.

1. *Magswitch 300 Amp Ground Clamp

(*Paid Link)

Reasons why I like the Magswitch:

This electro magnetic clamp has a knob to turn on and off. The Magswitch has a lightly curved base allowing it to better cling to curved surfaces. The fins on this magnetic clamp helps the clamp stay cool while your welding allowing it to keep its magnetism.

It supports a max welding amperage of 300 amp with 50% duty cycle. This means over a 10 minute period you can use this clamp for 50% of the time – five minutes.

It is available in 600 and 800 amp sizes and holds up to 90lbs in weight. But a maximum of 20lbs with vertical shear loads (a lot less holding power for those vertical welds).

The weight of the ground clamp itself is 2 and a half pounds so factor this in when you work out whether this clamp has enough magnetism for you to use with the weight of your ground cable.

2. *Strong Hand Powerbase Grounding GM203 300 Amp

(*Paid Link)

Reasons why I like the Strong Hand Powerbase:

This welding ground magnet uses a powerful rare earth magnet. Shaped in a V to help with curved surfaces.

It has a lever to allow you to turn on and off the magnet. You connect your ground cable to the top and the connection allows you to rotate 360 degrees. Useful.

The magnet can hold 44 lbs. of magnetic force.

A couple of inches in size make it small and convenient.

It is rated to operate at 300 Amp @ 60% Duty cycle. This means that over a ten minute period this clamp gives you 6 minutes welding time.

The Strong Hand Powerbase is also available in a 500 Amp size. The 500 Amp size and can grip with a force equal to 110 lbs. with its magnetic field.

3. Welding Grasshopper

The professionals love the Welding Grasshopper. These magnetic grounding clamps are designed specifically to prevent arcing at the magnetic ground.

They have been used for years in the pipe industry. Manufactured by Sawyer, unfortunately these magnetic grounding clamps are only available through their network of distributors.

Contact Sawyer Manufacturing via their site for enquiries.

Last Words

I hope my article has given you food for thought on choosing a magnetic ground clamp for your welding.

They are really best attached to clean bare steel for the best ground collection. But that is true for traditional ground clamps as well.

Some people love using them and others hate them.

I suggest having both, a traditional ground clamp and a magnetic ground clamp for your welding. That way you can use either depending on the welding situation you find yourself in.