DeWalt 4.5 in - 5 in Variable Speed Grinder with FLEXVOLT ADVANTAGE Technology (Tool Only)

Why variable speed matters here

Variable speed on an angle grinder isn’t a luxury anymore; it’s a necessity when you bounce between steel, stainless, aluminum, masonry, and finishing tasks. After putting this grinder through a broad mix of real jobsite and shop work—weld cleanup, light polishing, cutting rebar and angle, and sharpening lawn equipment—the standout is how confidently it moves between materials. The six-position speed dial and electronic controls give it a range that most cordless grinders simply don’t have, and the added muscle from FLEXVOLT Advantage puts it into a different category when you need it.

Power and speed: the FLEXVOLT Advantage difference

On standard 20V MAX packs, the grinder is fully capable for everyday cutting and grinding. Pair it with a FLEXVOLT DCB606 or similar pack and the tool clearly unlocks more headroom under load. The motor doesn’t bog as easily, cut speed improves, and it holds RPM better in heavier grinds. DeWalt claims up to 48% more power with FLEXVOLT compared to a 5Ah 20V pack; while I don’t test with lab instruments, the in-hand difference is obvious, especially on thicker material and when pushing a 5-inch wheel.

Max speed is 9,000 RPM, and the six-speed dial is well spaced:

• Speeds 1–2: Great for wire wheels, conditioning discs, and working softer metals without gouging.
• Speeds 3–4: Sweet spot for flap wheels on mild steel and controlled deburring.
• Speeds 5–6: Full-send cutting and heavy grinding with Type 27 wheels.

The brake stops the wheel quickly after releasing the trigger, shaving time between cuts and reducing the chance of setting the tool down on a spinning disc.

Ergonomics and control

At around 3.9 lbs bare (62.7 oz) and roughly 13 inches long, balance is good with a compact 20V battery. With a FLEXVOLT pack, it gets nose-light and tail-heavy—as expected—but still manageable. The grip diameter is comfortable with gloves, and the two-position side handle keeps control predictable when you’re making sideways cuts or switching from right- to left-hand operations.

The speed dial is positioned so I can tweak settings with my off-hand without breaking stance. I would have liked a slightly more textured dial for gloved adjustments, but it’s not a dealbreaker. Vibration is well controlled for a cordless grinder; flap disc finishing on stainless at mid-speed feels composed, and there’s enough finesse to avoid chatter when feathering an edge.

Guard adjustments are straightforward, and the included Type 27 guard, side handle, hex key, and flange get you working immediately—just bring your own wheels and battery.

Safety systems that actually make a difference

Two electronic layers give this grinder a calmer temperament than many in its class:

• E-CLUTCH: If the wheel pinches or stalls, the motor shuts down in a blink. It’s subtle when it happens, and that’s exactly the point—energy gets cut before the tool can twist out of line.
• KICKBACK BRAKE: In a bind-up event, it stops the wheel fast and reduces tool movement. Combined with the standard electronic brake on trigger release, it helps keep hands and workpieces safer.

I intentionally induced a few mild pinches during rebar cuts and in a notch grind. Each time, the grinder reacted quickly and predictably. You still need good technique and PPE, but these systems lower the stakes when the unexpected happens.

Connectivity and dust control options

Two modern touches add jobsite value:

• Wireless Tool Control: Pair the grinder with a compatible DeWalt dust extractor for automatic on/off. It’s a big win when surface grinding concrete or tuckpointing with a shroud.
• Tool Connect chip pocket: Drop in DeWalt’s DCE042 chip (sold separately) and you can track the tool in Site Manager. For shops and crews, it’s an easy way to keep assets accounted for.

These features won’t matter to every user, but when you need them, they’re legitimately useful.

Battery selection matters more than usual

Because FLEXVOLT Advantage unlocks extra current delivery, your battery choice changes the tool’s character:

• Compact 20V MAX (e.g., 3Ah–4Ah): Best for light grinding, wire brushing, and overhead cuts. Great balance and lower fatigue.
• Standard 20V MAX 5Ah: Versatile daily driver setup. Good runtime and performance for most metalwork.
• FLEXVOLT 6Ah (DCB606) or larger: Noticeably more torque for aggressive grinding and thicker cuts. Heavier, but it pushes a 5-inch disc well.

On low to mid speeds, I can get a surprising amount done with a compact pack—enough to sharpen multiple mower blades and deburr edges without swapping. For sustained heavy grinding, a FLEXVOLT pack is the right call.

Real-world performance

• Cutting: With a quality cutting wheel, 3/8" to 1/2" stock and rebar are no problem. The tool tracks well, and the brake helps when making repeated cuts with a jig or guide.
• Grinding and blending: Flap discs at speed 3–4 produce controllable finishes on mild steel, and stepping down the speed reduces heat tint on stainless. The motor holds steady pressure without surging.
• Finishing: Non-woven conditioning discs benefit from the slower speed range; it’s easier to avoid burning thin material or carving into corners.

Across all tasks, the grinder feels like it’s working with you rather than asking you to muscle it along.

Durability, warranty, and system fit

Build quality is solid, with tight guard fitment and robust housing. It’s part of DeWalt’s expansive 20V MAX system, so most users will already have compatible chargers and packs. The warranty is standard for the brand: 3-year limited warranty, 1-year free service, and 90-day satisfaction guarantee.

One note: it’s sold as a bare tool. Factor in at least one 5Ah 20V pack or a FLEXVOLT pack if you don’t already own them.

What could be better

• Weight with FLEXVOLT: The added power is welcome, but a DCB606 shifts balance toward the rear. It’s manageable, just noticeable in prolonged one-handed cuts.
• Price premium for variable speed: You pay more than a single-speed cordless grinder. If you only ever do demolition cuts and rough grinding, you may not need the dial.
• Dial feel: Slightly more texture would improve gloved adjustments.

None of these are dealbreakers, but they’re worth considering as you match the tool to your work.

Who it’s for

• Metal fabricators and mechanics who need to move between cutting, blending, and finishing on the same tool.
• Remodelers who want cordless cutting/grinding power that pairs with dust extraction for masonry tasks.
• Pros already in the 20V MAX/FLEXVOLT ecosystem who want a safety-forward grinder with real variable speed control.

If your work is exclusively heavy demolition or you always run wide-open on a single speed, a simpler grinder might be a better value.

The bottom line

This grinder hits the right balance of control, safety, and power. Variable speed actually expands what you can do, FLEXVOLT Advantage gives you an extra gear when you need it, and the electronic safety stack makes daily use more predictable. Add in Wireless Tool Control and Tool Connect readiness, and you’ve got a modern cordless grinder that feels thoughtfully built for real jobs.

Recommendation: I recommend this grinder for pros and serious DIYers who value variable speed and safety features and who can take advantage of the 20V MAX/FLEXVOLT battery ecosystem. If you already own compatible batteries, it’s an easy upgrade that broadens what you can do with a cordless grinder. If you’re starting from scratch and only need a basic cutter, you may find better value in a simpler model—but you’ll miss the versatility that makes this one stand out.