DeWalt 4.5 in. Slide Switch Small Angle Grinder with Kickback Brake

Why I reached for this grinder

I grabbed this DeWalt 4.5-in grinder for a small steel gate repair that turned into an afternoon of cutting, beveling, and cleanup. I wanted something light, fast, and safe to run on a ladder and around tight corners without dragging a cord. After a few weeks of real use—cutting rusty bolts, trimming 3/8-in rebar, surfacing welds with a flap disc, and chasing a couple of mortar joints—I’ve got a clear picture of what this tool does well and where it grates.

Power and speed

This grinder is built around a brushless motor spinning a 4-1/2 in wheel at a no-load 9,000 RPM. In practice, it keeps discs in the sweet spot for cutting and general grinding. With a thin-kerf cutoff wheel, I could slice rebar and stainless screws quickly, and with a 60–80 grit flap disc it removes material fast without bogging unless I get heavy-handed. The brushless drive is a big plus—no brushes to replace, better efficiency, and less heat buildup during longer sessions.

There’s no variable speed, so it’s a metal-first machine. If you want to polish, work plastics, or run specialty wheels that prefer low RPM, this isn’t the one. For steel work, though, the fixed speed keeps things simple and strong.

Safety features that matter

Two electronic protections stand out:

• Kickback Brake: If the wheel pinches or stalls, the tool shuts down and stops the wheel quickly. It also brakes hard when you switch off normally. It’s not instant, but it’s fast enough to make a real difference. On a cutoff in angle iron that bound suddenly, the brake saved my wrist and the workpiece.

• Power Loss Reset: If a battery is drained or knocked loose while the switch is in the on position, the tool won’t restart when power returns. That’s exactly the behavior I want on a crowded jobsite.

These features are the kinds of “you don’t notice them until you do” protections that reduce risk without adding fuss.

Switch and ergonomics

The slide switch sits on top, forward of the grip, with a lock-on option. To lock it, you push forward and then press down. It’s positive and secure, but the motion is a little awkward with gloves, and it’s easier to operate right-handed than left-handed. I prefer paddle switches for work where I’m constantly repositioning or feathering power, and I’d love to see this model offered with that option. That said, once I got used to the motion, I worked for long stretches comfortably.

Bare weight is around 4.6 lbs, and with a 5Ah battery it balances nicely. With a 6Ah pack, it gets tail-heavy in a way that actually helps when grinding on a flat surface; up on a ladder, the extra weight is noticeable but manageable. The side handle threads in securely, and the overmold on the grip keeps vibration comfortable over time.

Runtime and batteries

Cordless grinders are honest about one thing: they eat batteries. On continuous heavy grinding (flap disc, moderate pressure), a fresh 5Ah battery gave me roughly 10–15 minutes of active grinding before sag set in. On intermittent cutting tasks, I could work through a small project on one 5Ah pack. If you’re planning a day of grinding, you’ll want multiple batteries or a corded backup. This grinder is compatible with 20V MAX packs; higher-capacity batteries help, and the brushless motor makes the most of them.

Guard, flanges, and wheel changes

The grinder ships with a Type 27 guard, inner and outer flanges, a side handle, and a hex key. The guard seats securely and stays put once locked. The spindle is the common 5/8–11, so most 4-1/2 in abrasives drop right on.

One design note: wheel changes use the included hex key for the outer flange rather than a traditional spanner wrench. The system works and gives a confident clamp, but if you’re used to a two-pin spanner, this is different muscle memory. There’s no onboard storage for the hex, so it’s worth adding a clip or keeping it in your pouch. I also like having a spare set of flanges in the kit, as they aren’t the industry-generic style you’ll find in every shop bin.

Dust, cooling, and maintenance

Metal grinding throws a lot of fines. The motor housing has intake screening to keep debris out; give those vents a brush or burst of compressed air every day or two, especially if you’ve been grinding overhead where chips rain down. I didn’t notice any overheating, even during longer flap-disc sessions. The brushless motor certainly helps keep temperatures in check.

Vibes, noise, and control

Noise is on par with other compact 4-1/2 in grinders—hearing protection is a must. Vibration is well-managed for the size, and the side handle does real work dampening chatter on coarser wheels. With a cut wheel, it tracks straight, and the brake encourages good habits—you naturally wait the second or so for the wheel to stop before you set it down, reducing the chance of runaway discs.

Real-world use

• Cutting: With a 0.045 in cutoff, it zipped through fasteners and light angle stock. The brake adds confidence on plunge cuts where binding is more likely.
• Grinding: A 60-grit flap disc removes material fast. Push too hard and you’ll feel the electronics intervene before a full stall—back off and keep the RPM up.
• Masonry: With the appropriate guard and wheel, it will trench small joints, but without dust extraction or variable speed, it’s a short, dusty affair. It’s a metalworker’s grinder first.

What I’d change

• Switch feel: The slide/lock motion is secure but a bit awkward with gloves. A paddle-switch variant would be welcome for control-sensitive work.
• Hex-flange system: It’s solid but nonstandard. Onboard hex storage would solve half the annoyance.
• Kit value: At this price as a bare tool, a case or at least onboard tool storage would be nice. Batteries and charger are sold separately, as expected in a pro lineup, but factor that into your budget.

Warranty and service

DeWalt backs it with a 3-year limited warranty, 1 year of free service, and a 90-day satisfaction guarantee. That’s solid coverage and aligns with what I expect from a pro-grade cordless tool.

Tips for getting the most out of it

• Use thin-kerf cutoff wheels and let the RPM do the work—forcing cuts only invites binding.
• Step up to 5Ah or 6Ah batteries for meaningful runtime; bring at least two packs for continuous work.
• Keep the intake vents clean. A quick blast of air between tasks goes a long way.
• Respect the brake: wait for the disc to stop before setting the tool down.
• Match the guard to the task—Type 27 for grinding; use the correct guard and wheel for cutting.

Recommendation

I recommend this grinder for anyone already invested in the 20V MAX system who wants a compact, high-speed metalworking tool with real safety tech. The brushless power, fast electronic brake, and power-loss reset make it a confident choice for cutting and general grinding, especially in places where cords are a hassle or a hazard. Be prepared for the battery appetite—have a couple of higher-capacity packs on hand—and know that the slide switch and hex-flange approach may not be everyone’s favorite. If you’re grinding all day at a bench, a corded grinder will still be the better value. For mobile metal work, punch-list fixes, and jobsite cutting and cleanup, this DeWalt hits the mark.