DeWalt 7 in. (180 mm) Medium Angle Grinder

7 in. (180 mm) Medium Angle Grinder

Features

  • 13 Amp motor
  • No-load speed ~8,000 RPM
  • 7 in (180 mm) Type 27 guard (adjustable, keyless)
  • Spindle lock for single-wrench wheel changes
  • Two-position side handle (rear-handle design)
  • Sealed ball and roller bearings for motor longevity
  • External brush caps for servicing
  • Operates on corded AC (AC/DC capable in some listings)
  • Includes wheel, guard, side handle, hex key, inner and outer flange

Specifications

Amperage 13 A
Disc Diameter 180 mm (7 in)
Arbor / Spindle Size 5/8-11
No Load Speed 8,000 RPM (nominal)
Max. Watts Out (Uwo) 2250 W
Rated Wattage (Listed On Some Sources) 1,450 W
Product Weight 4 kg (≈11.6 lb)
Product Length 405 mm (≈15.9 in)
Product Height 120 mm (≈4.7 in)
Sound Pressure 94 dB(A)
Wheel Type Type 27 (depressed center)
Power Corded (120 V, 50/60 Hz)
Warranty 3 Year Limited Warranty; 1 Year Free Service; 90-Day Satisfaction Guarantee

Corded 7 in (180 mm) angle grinder for metal grinding and cutting. It is powered by a 13 A motor with an approximate maximum output rating and a no-load speed of about 8,000 RPM. The tool includes a Type 27 guard to help redirect sparks, a spindle lock for single-wrench wheel changes, and a two-position side handle (rear-handle design) for user control. Sealed ball/roller bearings and external brush caps are provided for maintenance access.

Model Number: DW840
View Manual

DeWalt 7 in. (180 mm) Medium Angle Grinder Review

4.2 out of 5

A straightforward 7-inch grinder that leans into grinding, not gimmicks

I put the 7-inch grinder to work across a few typical tasks: knocking down welds on structural steel, beveling plate, and scraping thinset off a slab with a cup wheel. It’s a simple, old-school corded grinder with a 13-amp motor and a no-load speed of about 8,000 RPM. What stood out over a couple of weeks wasn’t a flashy feature or a novel control—just consistent power delivery, predictable handling, and the kind of serviceability you appreciate in a tool meant to be kept for years rather than replaced.

Build and ergonomics

At roughly 11.6 pounds, this is not a compact grinder, but the weight feels honest and well-balanced. The rear-handle layout and long body give you leverage, which helps when you’re grinding horizontally on a bench or running along a floor. The two-position side handle threads into either side, but there’s no top position and it’s a basic, non–anti-vibration design. I would have liked a more refined handle with some damping and a third mounting point; after long passes with a coarse wheel, you feel more buzz in the hands than on some premium 7-inch units.

The Type 27 guard is keyless and easy to index. It pivots cleanly and holds position without drama, which makes it trivial to redirect sparks. The guard sits close enough to keep the footprint tidy but gives the wheel adequate clearance—it never rubbed or chattered during my testing with 7-inch depressed-center abrasives and a diamond cup wheel.

Fit and finish are workmanlike. The housing is robust, the spindle lock is positive, and the flanges/inner nut are standard 5/8-11. The external brush caps are a nice touch; if you’re familiar with brush changes, you can keep this motor in good shape without cracking the case. Sealed ball and roller bearings also suggest longevity, and the grinder never developed play or whine as I worked it.

Power and speed in real use

On paper, 13 amps at 8,000 RPM puts this grinder a notch below the 15-amp bruisers that dominate the heavy-duty segment. In practice, the difference is mostly felt when you bury the wheel. With a 7-inch Type 27 grinding disc, it maintained speed well under moderate to firm pressure, with a smooth recovery if I pushed into a corner and leaned on it. You can bog it down if you treat it like a cutoff saw in thick stock, but for weld cleanup, bevel prep, and general fabrication, the power feels sufficient and the higher RPM keeps the grind rate lively.

With a 7-inch diamond cup (paired to an external shroud and vac), thinset removal was a non-issue. The motor held steady, and the body length helped keep the head flat to the slab. The grinder runs a bit hotter than some 15-amp units if you keep it under sustained load for extended sessions, but I never tripped a breaker or felt thermal fade.

Noise is in the expected range—listed at 94 dB(A)—so hearing protection isn’t optional. Vibration is present but not excessive for a 7-inch grinder; most of what you feel comes through the simple side handle. If you do a lot of overhead or vertical grinding, the lack of an anti-vibe handle is the biggest ergonomic compromise.

Controls and wheel changes

The spindle lock is well-executed and didn’t slip while swapping wheels. Single-wrench changes are fast, and the guard’s tool-free adjustment means you aren’t hunting for a screwdriver just to change spark direction. Little things like that add up when you’re bouncing between materials and tasks.

I won’t speculate on the switch design beyond saying it’s positive and predictable; I didn’t experience accidental shutoffs or sticky engagement. The cord strain relief is robust, and the housing never rattled or creaked even after some ungraceful set-downs on concrete.

What it excels at

  • Heavy stock removal with Type 27 grinding wheels
  • Beveling and chamfering plate and tube
  • Surface prep on steel
  • Concrete/thinset removal with a cup wheel and dust collection
  • General fab work where stability and reach matter more than compactness

The grinder feels most at home in metalwork and concrete prep. Its balance helps keep lines straight, and that 8,000 RPM gives grinding wheels some extra bite without feeling twitchy.

Important limitations and safety notes

Guard compatibility matters. This grinder ships with a Type 27 guard and is intended for depressed-center grinding and similar operations. Flat Type 1 cut-off wheels and many diamond cut-off blades are not compatible with a Type 27 guard, and a Type 1 guard for this particular model is not generally available. I did not use Type 1 cut-off wheels or flat diamond blades on this grinder, and I wouldn’t recommend doing so. If your primary goal is cutting pavers, stone, or tile with a flat diamond blade, choose a grinder that supports a Type 1 guard or use a dedicated cutoff tool with an enclosed shroud.

Also note the speed rating: 7-inch wheels should be rated at or above the grinder’s 8,000 RPM no-load speed. Most pro-grade 7-inch abrasives are, but always double-check.

Dust management

There’s no built-in dust solution, which is standard for a metal grinder. For concrete work, I ran a clamp-on dust shroud and a high-CFM vac. The powerhead is stout enough to handle the added drag of a shroud/cup combo without stalling, and the guard stays out of the way. If you’re doing interior slab prep, a proper shroud plus PPE (respirator, hearing, eye protection) is a must.

Serviceability and durability

I like seeing external brush caps on a grinder in this class. Brushes are consumables; making them easy to access means you’ll replace them before they arc or damage the commutator. The bearings stayed quiet, and there’s enough sealing in the head that grinding dust didn’t migrate inside as long as I kept the guard oriented properly. DeWalt’s warranty stack—3-year limited warranty, 1-year free service, 90-day satisfaction guarantee—adds some peace of mind for a corded tool you may keep a decade.

How it stacks up

Against 15-amp competitors, this grinder gives up some raw torque but remains very capable for sustained grinding. If you live in heavy cutoff work or routinely hog off material with aggressive ceramic wheels, the extra amperage of a 15-amp motor is noticeable. If your workload leans toward prep, cleanup, beveling, and occasional concrete surface work, the 13-amp motor at 8,000 RPM hits a sweet spot of speed, control, and manageable weight.

Ergonomically, it’s behind the best-in-class units that offer 3-position or anti-vibe handles. Conversely, it wins on simplicity: fewer parts, straightforward guard, and easy service points. Some listings note AC/DC capability, but mine ran on standard 120V AC; if you need DC compatibility for field work, confirm the rating before you buy.

Who this grinder is for

  • Fabricators and welders who do more grinding than cutting
  • Remodelers needing a reliable powerhead for cup-wheel concrete prep
  • Pros who prioritize serviceability and predictable handling over maximum amperage
  • Users who are comfortable with a rear-handle, two-position layout

Who should look elsewhere: anyone planning to run flat Type 1 cut-off wheels or diamond blades as a primary task; anyone who needs an ultra-refined vibration profile or a lighter, compact body for overhead work.

The bottom line

This 7-inch grinder feels like a solid, no-nonsense workhorse built around grinding, not cutting. It’s powerful enough for daily fab tasks, holds speed under load, and pairs well with cup wheels for concrete prep. The guard is easy to adjust, wheel changes are quick, and the serviceable design should keep it running for years with basic maintenance.

It isn’t perfect. The side handle is basic and only offers two mounting positions, there’s no anti-vibration hardware, and you can’t (and shouldn’t) use it with Type 1 cut-off wheels or most flat diamond blades. If your workflow demands those, pick a model that supports a Type 1 guard or a dedicated cutoff tool.

Recommendation: I recommend this grinder for metalworkers and remodelers who need a dependable 7-inch platform for grinding and surface prep and who understand its guard limitations. If you primarily cut with flat diamond or abrasive cutoff wheels, choose a different tool that properly supports Type 1 accessories; otherwise, this grinder is a reliable, serviceable choice that does its core job very well.



Project Ideas

Business

Mobile Rust Removal & Surface Prep

Offer on-site rust/paint removal for trailers, gates, railings, and metal furniture using wire cups and flap discs. Package with priming/painting upsells and charge by panel/linear foot for predictable pricing.


On-Site Weld Cleanup & Fabrication Support

Serve local welders and makers by grinding welds flush, beveling joints, and deburring parts on demand. Bill hourly or per part, and add rush fees for same-day finish work before delivery or coating.


Custom Metal Signage & House Numbers

Design and produce metal address numbers, business logos, and plaques. Use the grinder for cutting, edge finishing, and brushed textures; offer powder-coat or clear-coat finishes and installation as add-ons.


Landscaper Paver/Stone Cutting Service

Provide precise paver and masonry cuts on job sites with diamond blades, plus edge chamfering for clean lines. Target landscaping crews who prefer to outsource cutting to speed up installs.


Lawn & Garden Tool Tune-Up Days

Host pop-up sharpening and clean-up events for mower blades, shovels, hoes, and shears. Use flap discs for edge refresh and rust removal; sell seasonal maintenance packages to neighborhoods and HOAs.

Creative

Industrial Coffee Table

Build a steel-and-wood coffee table: cut angle iron and square tube for the frame with cut-off wheels, then blend and flush the welds using grinding wheels and flap discs. Finish with a brushed metal look by progressively finer flap discs and clear coat to seal.


Horseshoe Coat Rack & Wall Art

Create a rustic coat rack using welded horseshoes on a flat-bar backer. Use the grinder to remove rust with a wire cup, bevel joints for stronger welds, and smooth all edges for a clean satin finish.


Rebar Garden Trellis/Plant Stand

Cut and shape rebar into geometric trellises or multi-tiered plant stands. Grind down spatter and sharp ends, then add a textured, weathered finish with a flap disc before painting to resist corrosion.


Custom Metal Silhouette Yard Sign

Cut simple silhouettes or monograms from 1/8 in steel plate using cut-off wheels. Chamfer and deburr the edges for a professional profile, then apply a patina or brushed finish and a UV-stable clear coat.


Brushed Steel House Numbers Panel

Fabricate a rectangular steel panel and mount laser-cut or hand-cut numbers. Use the grinder to create uniform brush lines (single direction) and soften all edges; finish with standoff mounts for a floating look.