Table of Contents
Introduction
Let's talk about angle grinders for a second. If you've been in the trades for any length of time, you've got a brand you trust. A lot of guys swear by Metabo, and honestly, that's a legitimate opinion. Metabo makes some of the best grinders on the market, and nobody is going to argue with you on that. This article is part of my ongoing collaboration with Hilti, and with a long history with the brand, I know what they're capable of. But after running the Hilti AG 4D-22, I'd take this one. And I don't say that to be controversial; I say it because it's where I landed after actually using it. It's smooth, it's powerful, the safety features are legit, and it just feels right in your hands. Pair it with the Nuron battery platform, and you can't beat it. So let's jump into this and see why I feel this beats the Metabo.
Build Quality and First Impressions
The AG 4D-22 is a 4.5-inch cordless angle grinder running on the Nuron 22V platform, and the first thing you notice is how solid it feels. The balance is good, the grip is slim, which matters when you're running it for a while, and nothing about it feels like Hilti cut corners to make it cordless. This is a working tool built for guys who use grinders all day, and it feels that way.
The brushless motor is putting out the equivalent of an 8-amp corded grinder, which is a number worth paying attention to. That's not cordless tool marketing math; that's actual usable power that translates to real performance when you're cutting rebar, grinding welds, or working concrete. Running at 7,700 RPM no load, and the disc stops in under two seconds when you let off. That quick-stop feature is something you quickly appreciate when you're moving around a job site.
Power and Performance
This is where the grinder earns its keep. The brushless motor delivers consistent power through the cut without the drop-off you feel on lesser cordless grinders when you put some pressure on them. I ran it on concrete, ground down a patch of my walkway, and worked a small curb I built on my driveway, and it just handled everything without complaint. The Nuron battery is doing a lot of heavy lifting here. Sustained power delivery is where cordless grinders have historically fallen short - the Nuron platform closes that gap in a way that actually matters when you're working.
The 1.14-inch max cutting depth covers rebar, pipe, sheet metal, and light concrete cutting without any issue. For the work most guys are doing with a 4.5-inch grinder day to day, this thing is more than capable.
Safety First
The AG 4D-22 has a paddle switch with a dead man's trigger, meaning the second you let go it stops. No lock on, no accidental engagement, no disc spinning when you set it down. For a grinder that's running at 7,700 RPM, that's not a feature; that's a requirement. Hilti got this right.
The 3D Active Torque Control is the other safety feature worth talking about. If the disc binds and kicks back, the ATC shuts the tool down before it torques hard against you. And it works in three dimensions, not just the standard single plane protection you get on most grinders. If you've ever had a disc catch on something and felt that violent rotation, you know exactly why this matters. The intake screen on the battery attachment area also keeps debris out of the motor, which, on a grinder doing concrete and metal work, is something you want to pay attention to long term. For me, the 3D ATC is an amazing feature and worth every penny.
The Guard and Arbor
The guard on the AG 4D-22 adjusts with a button; no tool required. You push the button, rotate it where you need it, done. Two seconds and you're set up for the application. It sounds simple, but anyone who has fought with a guard on a grinder knows how much of a difference a tool-free adjustment makes when you're switching between applications on the fly.
The arbor underneath is standard 5/8 inch 11 thread which means you're not limited to Hilti discs. Whatever you're already running on your other grinders is going to work here. A flange wrench comes with the tool, and the whole disc change process is straightforward.
The Side Handle
The side handle on the AG 4D-22 gives you real control over the tool, especially on heavier grinding applications where you need both hands. It's comfortable, it's positioned well, and it doesn't get in the way when you don't need it. For overhead work or anytime you need that second point of contact to keep the grinder exactly where you want it, this is what makes the difference between a controlled cut and a sloppy one.
Discs and What You Can Do With This Thing
Standard 5/8 inch 11 thread arbor means your whole disc inventory transfers over without buying anything new. I'm running a diamond blade for concrete and masonry cutting, a diamond cup wheel for surface grinding and prep work, and standard grinding discs for metal. All three are in the pictures, and all three are what you'd expect to reach for on a 4.5-inch grinder depending on the application.
The diamond blade handles concrete cutting, masonry, stone, and roof tiles. The cup wheel is what you want for surface prep, coating removal, and concrete grinding where you need to flatten or clean a surface. The grinding discs cover your metal work, weld grinding, deburring, and finishing. If you're doing rebar, pipe, or sheet metal, that's your disc. Nothing revolutionary here, just a grinder that runs all of them the way it's supposed to, with the power to back it up.
Tools In Action
I put the AG 4D-22 to work on a couple of real projects around the house. I built a small curb on my driveway and used the grinder to clean up the edges and surface, then I had a patch on my walkway that needed grinding down to blend with the surrounding concrete. Both applications are exactly what a 4.5-inch grinder is made for, and the AG 4D-22 handled both without any issues. Consistent power through the grind, no bogging, and the disc control made it easy to work precisely without taking off more than I wanted to. That's what you want from a grinder. It does what you tell it to do and doesn't fight you.
FAQ
Metabo makes a great grinder, I've said that and I mean it. But the AG 4D-22 beats them on power, beats them on the safety features with the 3D ATC.
It feels natural fast. Within about ten minutes of using it you stop thinking about it and it just becomes how the tool works. The disc stopping in under 2 seconds is something you notice and appreciate immediately.
The tool senses rotation in any direction, not just the standard kickback plane, and shuts down before it gets violent on you. In practice it's fast enough that you feel the start of the bind and then it's already stopped. It's not something you want to test on purpose but knowing it's there changes how confidently you can run the tool in tight spots or on applications where binding is a real possibility.
Final Thoughts
Look, I came into this knowing Hilti makes quality tools. That's never been a question. But angle grinders are a category where guys have strong opinions and strong brand loyalty, and for good reason. Metabo has owned that conversation for a long time and rightfully so.
But the AG 4D-22 changed where I land on this. The power is real, the 3D Active Torque Control is the best kickback protection I've used on a grinder, the paddle switch feels right, and the Nuron battery keeps it running the way a corded grinder would. I ran it on concrete, on metal, on a real job, and it didn't let me down once.
If you're a Metabo guy, I'm not here to tell you you're wrong. But I'd tell you to try this one before you make your next grinder purchase. That's all I'll say.
