Milwaukee 2880-20 M18 FUEL Brushless Lithium-Ion 4-1/2 in. / 5 in. Cordless Small Angle Grinder with No-Lock Paddle Switch

Why I keep reaching for this grinder

Cordless grinders used to be the “in a pinch” option. With the M18 grinder, that’s no longer the case. Over the past several months I’ve leaned on it for everything from slicing stubborn bolts in tight corners to cleaning up welds on plate steel, and it’s become the first grinder I grab—even when an outlet is right there.

This model runs on Milwaukee’s M18 batteries and accepts both 4-1/2 in. and 5 in. wheels via a standard 5/8"-11 spindle. The brushless motor, electronic safety features, and a no‑lock paddle switch set it up well for real jobsite use. It isn’t the lightest grinder you can buy, but it’s balanced, predictable, and powerful enough that I rarely feel like I’m compromising by leaving the cord behind.

Build, ergonomics, and controls

The shape and balance are on point. With a compact head and a slightly slimmer gear case than older cordless grinders I’ve used, it slips into confined spaces around brackets and inside cabinetry better than most. The anti‑vibration side handle actually does something—you still know you’re holding a grinder, but the tingling fatigue in your hands and forearms shows up later and less intensely.

The no‑lock paddle switch is the right call for this platform. It’s easy to feather on and off while repositioning, and it shuts the tool down the instant you release it. If you do a lot of long, continuous grinding passes (think dressing a long weld or beveling plate edge to edge), holding a paddle can be fatiguing compared to a latching switch. For everything else—cutoffs, quick blending passes, detail work—the control and safety benefits outweigh the hand fatigue.

Guard adjustments are straightforward, and the standard guard gives good coverage around the work without blocking your sightline. Wheel changes are simple with the spindle lock, and the flange nut is easy to manipulate with gloves on.

Safety features that matter

Two electronic layers stood out in real use:

• Electronic clutch: When the wheel pinches or binds, the grinder senses the event and cuts power quickly. I had it save a twisty wrist moment while cross‑cutting a rusty bolt embedded in a steel bracket—there was a quick burp and then silence, with no violent kick.

• Wheel braking: When you release the paddle, the wheel spins down quickly. That matters more than you think. It reduces the number of times you nurse a still‑spinning disc to a safe landing, and it limits the tool “walking” off a bench or ricocheting against nearby workpieces. It’s a quiet kind of safety you appreciate after a few hours.

Overload protection is tuned well. Push hard enough and the tool politely tells you to ease up rather than cooking itself. Back off for a second, and you’re back in business.

Power and performance

This grinder has the muscle for the work most of us buy a 4‑1/2 in./5 in. grinder to do. With a 0.045 in. cutoff wheel it slices angle iron and threaded rod decisively. With a flap disc it blends welds and knocks back mill scale without bogging. It doesn’t feel like a compromise compared to a solid corded 11–13 amp grinder for light to medium work.

If you lean on it with a hard wheel at a steep angle, eventually you’ll find the limits where a big corded unit or a larger-diameter grinder will pull ahead. That’s expected. In the size class this tool occupies, the brushless motor’s torque and the electronic control give it a composed, steady feel. There’s no surging or hunting, and the motor recovers quickly after you momentarily load it in a gouge.

Vibration control is very good for a compact grinder. The handle helps, but the way the head transmits feedback is also more muted than older cordless models I’ve used. After an afternoon of cutting and cleaning up steel brackets and pipe, my hands felt fresher than they usually do with a grinder this size.

Battery life and what to expect

Runtime is always the question with cordless grinders. The short version: expect to swap batteries on big grinding jobs, and plan your packs accordingly.

• For quick cutoffs, deburring, and touch‑ups, a standard 5.0Ah pack gets you through plenty of tasks without drama.
• For extended grinding on harder materials—or if you’re running a diamond wheel on masonry—high‑capacity “High Output” packs make a noticeable difference. The tool runs cooler and holds peak power longer between swaps.

As with any grinder, technique matters. Let the wheel do the work, choose the right abrasive (thin‑kerf cutoffs for cutting, quality flap discs for blending), and don’t stall the disc. Those habits extend runtime more than you might expect.

One note for cold weather: keep a spare battery in a warm pocket. Lithium packs sag sooner in the cold, and a warm battery will make the tool feel stronger from the first trigger pull.

Accessory fit and small details

The 5/8"-11 spindle means virtually any common 4‑1/2 in. or 5 in. accessory you already own will fit—cutoff discs, grinding wheels, flap discs, wire cups, and diamond blades. The head profile clears most hubbed wheels without drama. I also appreciate that the tool doesn’t fling sparks into your line of sight as readily as some—credit to the guard shape and the way the head vents are oriented.

Noise and spark management are typical for the class: it’s loud, and it throws a healthy rooster tail. Wear your protection and be mindful of what’s around you. Dust and metal fines didn’t seem to intrude into the vents, but any grinder benefits from a regular blast of compressed air to keep it breathing freely.

Durability and maintenance

After a steady diet of steel and the occasional masonry cut with a segmented diamond wheel, mine shows only the expected cosmetic scuffs. The brushless motor and electronics haven’t hiccuped. The paddle mechanism still feels crisp with a positive detent. As grinders go, it’s low‑maintenance: keep the vents clean, swap brushes—wait, you won’t, because it’s brushless—and periodically check the guard and handle hardware for tightness. That’s about it.

If warranty support matters to you, make sure you buy through a channel that keeps you in bounds for coverage in your region. That’s not unique to this tool, but it’s a practical note for a tool that may see hard use.

Where it excels—and where it doesn’t

Strengths:
- Cordless convenience without a big performance penalty. For most light and medium tasks, it stands shoulder to shoulder with a good corded grinder.
- Thoughtful safety: a no‑lock paddle, electronic clutch, and quick wheel braking add up to a calmer, safer day on the grinder.
- Ergonomics: balanced in hand, compact head for tight spots, and a side handle that actually tames vibration.

Trade‑offs:
- Continuous heavy grinding will chew through batteries. If your day is hours of hard-wheel grinding, a high‑amp corded grinder or a larger cordless platform will still be faster and cheaper to feed.
- The no‑lock paddle isn’t everyone’s favorite for long passes. It’s safer, but your hand works harder on marathon grinds.

Practical tips for getting the most out of it

• Pair it with high‑capacity M18 packs for heavy work; standard packs are great for quick cuts and touch‑ups.
• Keep two batteries in rotation on grinding‑heavy days to avoid work stoppages.
• Use quality abrasives. Cheap wheels glaze faster, cut slower, and drain batteries quicker.
• Let the clutch be your teacher. If it trips, adjust your angle and pressure rather than fighting it.
• Reposition the guard as you switch between cutting and grinding; the coverage is there, but it only works if you aim it.

Recommendation

I recommend the M18 grinder to anyone already on Milwaukee’s 18V platform and to pros or serious DIYers who want a cordless grinder that feels like a primary tool, not a compromise. It’s powerful, composed, and notably safer than many rivals thanks to its electronic clutch, quick braking, and no‑lock paddle. If your workload is dominated by long, heavy grinding sessions, plan on high‑capacity batteries—or keep a corded grinder in the shop for those days. For everything else, this is the grinder I trust to travel, to reach into tight quarters, and to handle the bulk of cutting and surface prep without tying me to an outlet.