Hobart Airforce 40i Plasma Cutter Review

The Hobart Airforce 40i has almost everything you could ask for in a plasma cutter.

It’s powerful, portable and is packed with the latest technology to give you an unprecedented plasma cutting experience.

From its compact inverter design to its Auto-Refire technology, the list of features goes on and on.

You’ll have to keep reading to find out more.



  • Inverter design
  • Auto-Refire technology
  • XT40R torch w/ 12-ft lead
  • Post-flow air cooling
  • Fan on demand
  • Lightweight and portable
  • Hooks up to engine driven welders
  • Thermal overload protection
  • 50% duty cycle
  • Easy to use controls


  • Ground clamp could be improved
  • Only 240 V
  • A bit costly

What’s Good?

Inverter design

Inverter plasma cutter technology has come a long way since its introduction a few decades ago.

They used to be unreliable and mediocre at best. Like any new technology, it had its hiccups and obstacles to overcome in the beginning.

As the technology advanced they became more reliable and more powerful.

Now inverters are standard among welders and plasma cutters – including the Hobart Airforce 40i.

That’s how they’re able to fit such immense power into such a tiny package.

Only a few years ago if you wanted a plasma cutter with such power you would need to buy a machine that weighed hundreds of pounds.

You wouldn’t even consider trying to move it around the shop.

Instead of storing the power in a huge transformer with spools of heavy copper wire, the power is electronically stored in sophisticated silicone based circuitry which is then transferred to a much smaller transformer to put out the power needed to slice through metal.

Inverters are the way of the future and the Hobart Airforce 40i is right on the cutting edge.

Lightweight and portable

Because of it’s inverter based design the Hobart Airforce 40i is incredibly lightweight for the amount of power it’s capable of putting out.

Weighing roughly 31 lbs, and about the size of a few pizza boxes stacked vertically, this plasma cutter is so light and small you’ll think there’s something missing.

There isn’t.

Portability is a major selling point with this rig. The heavy duty handle ensures you’ll have no problem moving it around the shop or even to and from job sites.

No matter how remote of an area you need to take it, this unit can handle it.

Which brings us to the next feature.

Hooks up to engine driven welders

Engine driven welders are basically gas powered welders that can double as a generator to power whatever you need it to.

The Hobart Airforce 40i easily hooks up to any engine driven welder with a 240V outlet and is able to cut 3/8” – 5/8” steel like ripping apart wet tissue paper.

With this capability there’s no limit to the things you can cut. Just imagine the possibilities.

Auto-Refire technology

Hobarts Auto-Refire technology is one of the most impressive features we’ve seen on a plasma cutter.

Simply put, there’s nothing stopping the Hobart Airforce 40i from chopping through metal.

This feature allows you to easily cut through all sorts of metal: from dirty and rusted to painted to perforated and expanded metal.

With lesser plasma cutters the arc cuts out as soon as there is a gap or hole in the metal.

You then have to reignite the arc to continue.

If you regularly cut perforated or expanded metal you know how annoying and tiresome this gets. Especially if you use plasma cutters all day.

Auto-Refire technology switches in and out as fast a needed when cutting through expanded metal automatically so there is no need for re-triggering the arc every time.

This not only saves time but reduces the inevitable hand fatigue that comes from cutting all day.

You’ll be able to cut longer, better and more comfortably than you could have imagined.

XT40R torch w/ 12-ft lead

The Hobart Airforce 40i comes standard with the new high-performance XT40R torch and it’s one of the best plasma cutter torches available today.

It’s ergonomically designed to give you optimal comfort during those long days that just don’t seem to end. Additionally the trigger safety is perfectly located to reduce hand fatigue and increase comfort.

The XT40R torch provides more efficient cooling than its predecessor that, while not too significant, will provide savings on energy consumption.

It features a flexible 12-foot lead that allows you total freedom of movement to save you from moving the plasma cutter itself around.

Finally, replacement tips and consumables, from the XT series of plasma torches (which are the same torches Miller uses) are economical and long lasting.

Post-flow air cooling

Even though the tips and consumables are inexpensive and long lasting, the more life you can get from them the better.

Which is why the post-flow air cooling feature is so important.

After the trigger is released and the cutting action stops, a stream of cool air continues to flow for a short period.

This extends the life of the tips significantly, saving you not only money but the time having to replace them on the regular basis.

Fan on demand w/ Wind Tunnel technology

Fan-on-demand is pretty much what it sounds like.

Rather than the inefficiency of having a constantly running fan, the fan only turns on when the internal temperature passes a certain threshold.

There are several benefits to this:

Noise reduction – a workshop is already loud enough. There’s no need to add more noise.

Reduced energy consumption – While it’s probably not significant, only having the fan run when it needs to will save on energy and thus save on costs.

Less grit and dust – Whether you can see it or not, there are millions of dust, grit and metal particles floating through the air at any given time in most shops. The less time the fan is on the better.

That brings me to the next feature: Wind Tunnel technology.

I’m a bit confused on this one.

I can’t find any information online except that it “prevents abrasive dust and particles from damaging internal components.”

I’m not going to pretend like I know how it works, but anything that extends the lifespan of your investment sounds like a good thing.

Thermal overload protection

Most new fabrication equipment – welders/plasma cutters – have a built in thermal overload protection feature but the Hobart Airforce 40i is a bit different.

Instead of just reacting to the temperature and shutting down after it hits a certain point, the Airforce shuts down if 3 things occur: it gets too hot, the fan is blocked or you pass the rated duty cycle.

This is what lets it withstand gruelling environmental conditions without having to worry about destroying the rig.

50% duty cycle

The Hobart Airforce 40i boasts an impressive 50% duty cycle at the maximum output.

Just like with welders, that means for every 5 minutes you cut you need to let it rest for another 5 minutes before starting again.

This gives the plasma cutter time to cool off to prevent damage to the machine.

Easy to use controls

The controls on the front panel of the Hobart Airforce 40i are so easy and intuitive a child could operate it.

There’s a power switch to turn it on and off.

And there’s also a giant knob that adjusts the amperage.

That’s it.

You don’t even have to remove your gloves.

Power Factor Correction and Line Voltage Compensation

Both of these features assist with power reliability so you have one less thing to worry about when your dealing with hot plasma and sharp metal.


Power Factor Correction draws up to 30% less amperage than similar powered plasma cutters while still maintaining the same power output.

This not only saves energy but it allows you to more readily plug the unit into an extension cord for an increased work area. Additionally it reduces the likelihood of tripping the circuit breaker caused by voltage drops.


Despite the rated voltages of power outlets the actual power can fluctuate at any given time. Thanks to the Line Voltage Compensation feature the power source remains relatively steady +/- 15% so you can make much cleaner cuts.

What’s Bad?

Ground clamp could be improved

Cutting power is highly dependant on the units ability to stay grounded.

The ground clamp that comes with it works perfectly but it feels a bit flimsy.

Besides the consumables it will probably be the first thing that needs replacing, although you’ll easily get a few good years out of it.

Only 240 V

The Hobart Airforce 40i is a powerhouse and to run on maximum power requires a 240V outlet.

It’s understandable.

But it would be nice to have a multi-voltage plug or the ability to swap power cords to 120 V for those times when you don’t need all 40 amps.

A bit costly

Sure it’s a bit expensive but because it’s a Hobart you know it’ll last a long, long time.

For as long as the Hobart lasts you’ll go through 3-4 cheaper machines.

Is it really worth the headache to save some money initially?

Probably not.

The Verdict

Hobart has done it again.

When it comes to fabrication equipment they seems to knock it out of the park every time and the Hobart Airforce 40i is no exception.

It has the power to cleanly cut through 5/8” thick mild steel and sever up to 7/8” all from a compact box that weighs around 31 lbs – an impressive feat of engineering.

The features that this plasma cutter boasts are industry leading and the technology behind it is on a whole other level.

Cutting with the Hobart Airforce 40i is an experience every fabricator needs to have.

Specs and Features


Weight: 31 lbs

Size: L14″ x W8″ x H11″

Power Input: 240 V

Power Output: 40 A

Duty Cycle: 50% @ 40A

Cut Thickness: 5/8″

Severance Thickness: 7/8″

Warranty: 5/3/1 year