DeWalt 4-1/2 in. Angle Grinder

I reach for a grinder more often than I expect, and this 4-1/2-in cordless DeWalt has been riding in my kit long enough to prove what a modern battery-powered grinder can do—and where it still lags behind a stout corded model.

First setup and what’s in the box

As a bare tool, it arrives without a battery or charger. In the box with the grinder I used were two guards (a Type B with a clip-on Type A), a Type 27 grinding wheel, the side handle, and a wrench. Pop on the guard you need, thread the wheel, snug the flange with the spanner while holding the spindle lock, and you’re working in minutes. The clip-on guard system is straightforward and makes it easy to switch from grinding (Type 27/B) to cutoff (Type 1/A) without digging for another guard.

A quick note on size: this is a 4-1/2-in grinder. Stick to 4-1/2-in wheels and accessories. The guard and clearances aren’t designed for 5-in wheels.

Ergonomics and controls

The body is slimmer than many 20V grinders and genuinely easy to choke up on when you’re in tight spots. The paddle switch has a positive lock-off that’s intuitive with gloves on, and there’s no lock-on. For me, that’s a plus for safety; for long, continuous grinding, you may miss a lock-on. The side handle threads in solidly and the vibration transmitted through the grip is well controlled for this class.

One detail that stands out is the forward exhaust. The cooling air moves out ahead rather than into your face, which sounds minor until you’re showering sparks and dust; it keeps the airstream from kicking debris back toward you.

Power and speed

DeWalt rates the brushless motor at up to 760 MWO with an 11,000 RPM no-load speed. Ratings aside, the grinder has the snap I expect from a compact corded unit when you feather the paddle—it jumps to speed quickly and maintains it respectably under load. In cutting tasks (rebar, galvanized strap, and stubborn framing nails), it tracked straight and didn’t bog unless I leaned too hard. On grinding and blending with Type 27 wheels and flap discs, it holds a usable cadence if you let the abrasive do the work.

This isn’t a brute for heavy beveling on thick plate—no 4-1/2-in cordless is—but for light fabrication, fast cutoff, bolt removal, and cleanup, the power is more than adequate. The brushless motor’s efficiency shows up in both runtime and responsiveness.

Brake and anti-kickback behavior

Two electronic features define this tool’s personality: the brake and the anti-rotation system. Release the paddle and the wheel coasts to a stop in roughly a second and change—my informal timing consistently landed just over a second with a cutoff wheel, a touch longer with a full grinding disc. The quick stop is a real safety benefit when repositioning or setting the tool down.

The anti-rotation system monitors for pinch, stall, or bind-up and shuts the motor down instantly if it senses a spike. I intentionally pinched a cutoff wheel mid-cut; the grinder stopped immediately, and I had to cycle the paddle to get going again. It’s an extra step, but it prevents a minor bind from becoming a wrist-twisting event. If you’re used to older grinders, you’ll feel it intervene sooner than your instincts might expect—in a good way.

Guard system and wheel changes

The guard adjustments are simple and secure, and the conversion between the included Type B and the clip-on Type A is tool-free. For metal cutoff, the Type A guard offers better spark control and clearance; for grinding and flap discs, the Type B shield and depressed-center wheels are the right match.

Wheel changes are quick: the spindle lock engages positively, and one wrench is all you need. Compared to old two-wrench setups, this is faster and less fiddly. The lock button is recessed enough that accidental engagement is unlikely while the wheel is spinning.

Working in tight spaces

This grinder earns its keep in awkward corners. The reduced gripping diameter and the compact gear case let me get a cutoff wheel into stud bays and between hangers without pulling the guard off. On one remodel, I trimmed nails and brackets without having to reach for a corded unit or compromise on protection. That’s a meaningful upgrade in real-world use where removing a guard is a common but risky temptation.

Runtime and batteries

Pair it with a 5.0Ah 20V pack and you’ll get a practical amount of work between swaps—enough to sharpen a set of mower blades and still have juice for a handful of cuts. Grinding is the hardest hit on runtime, and thin-kerf cutoff wheels extend battery life noticeably. High-capacity packs (6–8Ah) stretch runtime further and add some welcome counterweight, though they do make the tool a bit tail-heavy. On the flip side, a compact 2.0Ah pack keeps the whole package very nimble for quick cuts, with the expected trade-off in endurance.

Plan on carrying spare batteries if heavy grinding is on the docket. That’s the nature of cordless grinders, not a knock specific to this one.

Dust, cooling, and noise

All grinders throw debris; this one manages heat well and doesn’t blow directly back at you. The forward exhaust helps keep your view clearer, but proper PPE is still non-negotiable. Noise levels are typical for an 11,000 RPM grinder: not obnoxious, but absolutely in hearing protection territory.

Asset tracking and serviceability

If you manage a fleet, the Tool Connect chip-ready compartment is a nice touch. Install the optional chip and you get asset tracking and some management features without changing how the tool feels in hand. For most solo users, it’s a set-and-forget capability, but on shared crews it can save headaches.

On the service side, the brushless motor means fewer wear components than brushed designs. Routine maintenance is mostly limited to keeping vents clear and staying on top of wheel condition. The warranty—3-year limited, 1-year free service, and 90-day satisfaction—adds a layer of reassurance.

What it’s not

• It’s not a 5-in grinder. Use 4-1/2-in wheels and guards as intended.
• It’s not a lock-on grinder. If you rely on a lock-on for long surface grinding sessions, you’ll need to adjust or choose a different switch style.
• It’s not a replacement for a 13–15A corded grinder on heavy beveling or aggressive stock removal. It can do the work in short bursts but will be slower with more frequent battery changes.

Tips from use

• Use thin cutoff wheels with the Type A guard for faster, cooler cuts and longer battery life.
• For sharpening mower blades, a 60–80 grit flap disc on the Type B guard gives you control and a clean finish; let the brake stop the disc before flipping the blade.
• Keep a 5.0Ah battery as your default; carry a compact pack for overhead or ladder work where weight matters most.
• Don’t defeat the anti-rotation behavior by muscling through binds. Let it reset, free the wheel, and continue—it’s saving you from kickback.

Verdict and recommendation

This DeWalt 4-1/2-in cordless grinder is a well-executed balance of safety, power, and ergonomics. The brake and anti-kickback systems aren’t marketing fluff—they intervene quickly and predictably. The slim body, paddle switch, and forward exhaust make it genuinely easier to use in close quarters. And the guard system is practical, not an afterthought.

I would recommend it to anyone already on DeWalt’s 20V Max platform who needs a capable, compact grinder for cutting, cleaning up welds, bolt busting, and maintenance tasks. If you spend your days doing continuous heavy grinding, a high-amp corded unit (or a larger cordless grinder) is still the right primary tool. But for day-to-day field work, remodel jobs, metal fab punch lists, and yard equipment maintenance, this grinder earns its slot in the bag. It’s safe, quick to deploy, and powerful enough to handle the bulk of the work I throw at a 4-1/2-in wheel—without dragging a cord behind me.