Buy corded. For nearly everyone, a corded grinder is the right first tool: it costs a fraction of the cordless equivalent, never runs out mid-cut, and holds its power through the tenth minute of a long job. Buy cordless when the cable is the actual problem — working up a ladder, out on a gate, on a roof, anywhere there is no outlet — and buy it as a second grinder rather than a replacement.
One thing that has changed, though, and it cuts the other way: modern cordless grinders are more likely to have an electric brake and kickback detection than a budget corded one. If you cut a lot of thin section, that is a real safety argument for cordless that has nothing to do with the cable.
What’s Inside!
Quick Verdict
| What you’re doing | Buy | Why |
|---|---|---|
| Your first grinder, for a home workshop | Corded | Far more tool for the money, and nothing to charge before you start |
| Cutting a lot of steel, or long grinding sessions | Corded | Constant output. A cordless grinder is a battery-eating tool and this is the job that empties it |
| Fabricating at the bench | Corded | The outlet is right there. Paying for a battery buys you nothing |
| Gate, roof, ladder, field, site with no power | Cordless | This is the job the cable actually prevents, and the only one where it does |
| Quick cuts, moving around constantly | Cordless | Setup time drops to zero, which matters more than runtime on short cuts |
| You already own the battery platform | Cordless | The bare tool is much cheaper than the kit, and this is where the platform pays off |
| You want the safest tool available | Cordless, or a premium corded | Brake and kickback detection are far more common on cordless models |
An electric brake stops the disc in seconds; without one it coasts
Both types are equally capable of hurting you, and both need the same discipline — guard on, disc rating checked against the plate, face shield over glasses, two hands. But there is one genuine safety difference and it is not the cable. A grinder with an electric brake stops the disc within a couple of seconds of releasing the switch; without one, a 115 mm disc keeps spinning for far longer after you have set the tool down. Most people set it down before it has stopped. Kickback detection is the other one: sensors that cut power when the tool twists suddenly, which is the moment a bound disc becomes dangerous. Both features appear on cordless models much more often than on budget corded ones.
- Corded, specifically: keep the cord over your shoulder and behind you. A cord dragged into the disc is a live conductor cut in half, and outdoors or on a damp floor that needs a GFCI in the supply, not just care.
- Cordless, specifically: take the battery out before changing a disc. It is the equivalent of unplugging, and it is skipped far more often because there is no plug to pull.
- Both: check the disc’s rpm stamp against the tool’s plate every time. A disc rated below the grinder’s no-load speed can burst.
- Both: the guard stays on, positioned between the disc and your body.
- Cordless batteries get hot under a grinder’s current draw. A pack that is too hot to hold comfortably needs to rest, not go back on the charger.
Corded Angle Grinders
A corded grinder delivers its rated input power for as long as you hold the trigger. That sounds obvious until you watch a cordless one fade over a long cut—the corded tool does the same work in the tenth minute as in the first.
- PowerConstant, from wall power, at full rated output throughout
- RuntimeUnlimited – the only limit is the motor’s heat
- CostFar less for the same power, with no battery to replace later
- LimitationYou can only work where the cable reaches
The economics are the strongest part of the case. A cordless grinder plus two decent batteries and a charger costs several times a comparable corded tool, and the batteries are a consumable — they lose capacity over years whether or not you use them. Corded tools have no equivalent decay; the wearing parts are carbon brushes and a switch, and both are cheap.
The cable is a workshop problem, not a capability problem. An extension cord solves most of it, and a cord run over your shoulder rather than across the floor solves the rest. What it does not solve is a job with no supply at all — and that, rather than inconvenience, is the actual dividing line on this page.
Best Corded Grinders
Last update on 2026-09-23 / Affiliate links / Images from Amazon Product Advertising API
Cordless Angle Grinders
The freedom is the obvious part. The less obvious part is how hard a grinder works a battery: an angle grinder draws far more current than a drill or a driver, so runtime figures that feel generous on a cordless drill don’t transfer. A grinder empties a pack fastest, and a small battery on one is close to pointless.
- PowerClose to corded on a fresh pack, tapering as it discharges
- RuntimeMinutes of continuous cutting per pack, not hours
- BatteryGo large – a high-capacity pack is not optional on a grinder
- AdvantageZero setup, and brake plus kickback detection are common
Brushless motors closed most of the power gap. What they did not close is the energy gap: a cable carries as much energy as the tool can use, indefinitely, and a battery carries a fixed amount. On shortcuts, that never matters. On a morning of cutting sections, you are working around charge cycles.
The setup advantage is underrated, though. For a job that needs three cuts on a gate at the far end of a plot, a cordless grinder is out of the bag and cutting before a corded one has to run an extension cord. That’s when it wins outright, and it happens more often than people expect.
Best Cordless Grinders
Last update on 2026-09-23 / Affiliate links / Images from Amazon Product Advertising API
Side by Side
| Feature | Corded | Cordless |
|---|---|---|
| Power supply | Continuous from wall power | Battery, tapering as it discharges |
| Runtime | Unlimited, motor heat aside | Minutes of continuous cutting per pack |
| Output under load | Constant throughout the job | Strong on a fresh pack, falls away as it drains |
| Mobility | Cable length, or an extension cord | Anywhere |
| Setup time | Find an outlet, run the cord | None |
| Weight | Lighter tool, but tethered | Heavier with a large pack fitted |
| Cost | Much lower, no consumable battery | Several times higher with batteries and charger |
| Brake and kickback detection | Premium models only | Common, even mid-range |
| Long-term ownership | Brushes and a switch; both cheap | Batteries lose capacity with age regardless of use |
Where People Get This Wrong
- Buying cordless first. It’s the more pleasant tool and the more expensive one. As a first grinder, it buys convenience you rarely need at the price of power you always do.
- Pairing a cordless grinder with a small battery. A grinder pulls current at a rate a drill never does. A low-capacity pack gives you a few cuts and a hot battery.
- Mixing battery platforms. Two brands means two chargers and no spare cells when one dies mid-job. Pick a platform and stay on it.
- Running the cable across the work. The one hazard unique to corded, and the one that is entirely avoidable — cord over the shoulder, behind you.
- Changing a disc without removing the battery. No plug to pull means you skip the step. Take the pack out.
- Assuming cordless means less powerful, full stop. On a fresh high-capacity pack, a good brushless grinder is close to a corded one. The gap is in endurance, not in peak output.
Why the Cable Still Wins on Endurance
Both types use the same kind of motor doing the same work, so the difference is entirely in the supply. A power cord delivers whatever current the tool demands, for as long as you want it, and the tool’s limit is how much heat its own motor can shed. A battery holds a fixed amount of energy, and a grinder is the household tool that consumes it fastest.
That is also why cordless output tapers. As a pack discharges, its voltage falls, and a lower voltage means less speed and less torque at the disc — so the last cut of a pack is not the same as the first. A corded tool has no equivalent behavior; wall power does not sag because you have been working.
None of which makes cordless the lesser tool. It makes it a different one, whose advantage is measured in setup time and reach rather than in watts. If you want the middle ground on a corded tool — full power available but dialed down for polishing or wire brushing — that’s what controlling an angle grinder’s speed covers, and it only works on corded models.
Whichever you buy, handling is identical: safe angle grinder use applies to both, and if you’re still deciding whether a grinder is the right tool, angle grinder versus die grinder is the comparison to read first.
Corded vs Cordless Questions People Actually Ask
Is a corded grinder more powerful than a cordless one?
At peak, a good brushless cordless grinder on a fresh high-capacity pack is close. The difference is endurance: a corded tool holds that output indefinitely, while a battery’s voltage falls as it discharges, so speed and torque taper through the pack.
Can a cordless grinder cut metal?
Yes, easily. What it cannot do is cut metal all afternoon on one battery — a grinder draws far more current than a drill, so plan on battery swaps for any sustained cutting.
How long does a cordless grinder battery last?
Minutes of continuous cutting rather than hours, and it varies enormously with pack capacity, disc size and how hard you push. Light intermittent work stretches much further than continuous cutting does.
Which is safer?
Neither by default, but the features differ. Corded adds the cable hazard — a cord cut by the disc, and outdoors that needs a GFCI. Cordless models more often include an electric brake and kickback detection, which are real protections. A premium corded grinder with a brake is as safe as either.
Is it worth owning both?
If you work away from power regularly, yes — and in that order: corded first for the workshop, cordless second for everything the cable can’t reach. Buying both at once is rarely necessary.
What battery size do I need for a cordless grinder?
The largest capacity your platform offers. A grinder is the wrong tool to economize on packs for — a small battery gives a few cuts, gets hot, and leaves you waiting on a charger.
Can I use a speed controller on a cordless grinder?
No. External SCR controllers work by chopping the AC waveform, and a cordless tool has no AC supply to chop. Variable speed on a cordless grinder has to be built into the tool.
Corded First, Cordless Second
If you’re buying one grinder, buy the corded one — more power, more endurance, a fraction of the price, and nothing that degrades on a shelf. Add a cordless later, when you find yourself running an extension cord to a job that would take two minutes without it. That is the point at which the battery earns its money, and not before.
