The best angle grinders for welding

The short answer

Here is the thing nobody tells a new welder: you will use the grinder more than the welder. Fit-up is grinding. Cleaning mill scale and paint off a joint is grinding. Chamfering an edge so a weld can reach the root is grinding. Knocking a proud bead flat, cutting stock to length, removing a tack you placed in the wrong place, taking the slag ridge off a flux-core weld — all grinding.

Which is why ranking grinders on amperage, the way general tool roundups do, misses the point. Every 4-1/2 in grinder worth buying has enough power for weld work. What separates them is how the tool behaves when a disc grabs, whether the motor survives a shop full of conductive steel dust, and how much friction stands between you and changing a wheel.

What we ranked on, in order

1. What happens when the disc binds. This is first because it is the thing that injures people. A cut-off disc jamming in a kerf stops instantly while the tool keeps going, and the energy goes into your wrists. Two defenses exist: a mechanical slip clutch that lets the drive give way, and an electronic kickback brake that cuts power when it detects the tool rotating. We rank a tool with either above one with neither.

2. Whether the switch can be locked on. A non-locking paddle stops the disc the moment you let go. A lock-on switch means a dropped grinder keeps spinning across the floor with a live disc. For a welder — who is often putting the grinder down hot, in a cluttered shop, with gloves on — that is the single easiest safety feature to get right and it costs nothing.

3. Sealing against grinding dust. Weld shops are the worst environment an angle grinder sees. The dust is fine, abrasive and electrically conductive, and it is what actually kills these tools: it gets into the bearings and the armature, and the motor dies long before anything else wears out. A manufacturer that publishes a specific defense against it has thought about this use.

4. Tool-free guard and disc changes. Not convenience features. A guard that needs a wrench to move is a guard that comes off and stays off, and a wheel change that needs a lost spanner is the reason people cut with a grinding wheel. Removing friction from the safe choice is how the safe choice gets made.

5. Weight and grip, judged for sustained use. Published weight and grip circumference decide whether you can hold the tool steady for the twentieth minute. These matter most overhead, which for trailer, gate and frame work is where a lot of welding actually happens.

Raw amperage came last, deliberately. Between 7.5 A and 11 A there is a real difference in heavy stock removal and almost none in weld cleanup.

The four, on the specifications that actually differ

Two blanks in that table are the honest answer rather than a gap in the research. DeWalt does not publish a bare weight for the DWE402K on its listing, and the Metabo listing's only weight figure includes packaging. Printing either as a tool weight would have made the column look complete and been wrong.

Why 4-1/2 inch, and not bigger

A 7 or 9 in grinder removes material faster and is the wrong tool for welding. Three reasons, in order of how much they matter.

First, access. Weld cleanup happens in corners, inside angles and along fillets, and a large disc cannot reach into a joint. Most of the grinding a welder does is within an inch of a weld, in a place a 4-1/2 in disc barely fits.

Second, control. A large grinder has enough torque to take itself out of your hands when the disc catches, and it is heavy enough that you cannot stop it. The injuries are correspondingly worse.

Third, consumables. Four-and-a-half inch discs are the commonest abrasive size sold, in every type you need — grinding wheels, 1 mm cut-off discs, flap discs, wire cup brushes, surface conditioning discs. They are cheap, every hardware store has them, and that availability is worth more over a year than any single tool feature.

The one job the small grinder cannot do is cut thick plate accurately, and that is not a grinder problem. Past about 1/4 in a grinder is slow, loud and incapable of following a curve, which is where a plasma cutter earns its place — plasma cutter versus angle grinder is that comparison, and is a plasma cutter worth it is the honest version of the question.

The discs matter more than the grinder

Having spent this page on tools, here is the correction: for weld work the disc you fit changes the result far more than which of these four you own. Four types cover nearly everything a home welder does.

A grinding wheel — thick, rigid, usually 1/4 in — is for stock removal and knocking back a bead. A 1 mm cut-off disc is for cutting, edge-loaded only. A flap disc is the one most welders underuse: it blends and finishes a weld without the gouging a grinding wheel leaves, and it is what makes a bead look intentional. A wire cup brush removes mill scale, rust and paint without taking metal with it, which is the prep step that decides whether a weld fuses at all.

That last one is worth repeating because it is the commonest cause of a bad weld on a perfectly good machine. Mill scale is not metal, paint is not metal, and galvanizing is both not-metal and a fume hazard. The joint gets cleaned to bright steel first, every time — see beginner welding mistakes and, for what the fume side means, welding respiratory protection.

How we decided this

Published specifications only. Every figure on this page is the manufacturer's own published specification as carried on its product or retailer listing, read on the publication date. Where a listing published only a packaged weight, we left the cell blank and said why. We have not run, weighed or dropped any of these tools, we publish no scores, and we have tested nothing — which is stated plainly on how we pick.

We ranked for welding, not for tool reviews generally. The usual grinder roundup sorts by amps and finishes. The three things we put above amperage — kickback behavior, dust sealing and change friction — are the ones a weld shop actually tests, and they are why a 7.5 A tool is on this page above nothing and an 11 A one is not automatically first.

Availability checked before publishing. All four grinders were confirmed in stock and title-matched to their registry entries on the publication date.

Honest cons on all four, including the winner. The DeWalt has no published slip clutch. The Metabo is expensive and heavier. The Makita has a lock-on switch and the least power. The cordless one is a bare tool that needs a battery you may not own. Pick on which of those you can live with.

Next, if you have not bought the welder yet: what first welder to buy is the level-by-level decision, the welding starter kit checklist puts the grinder in order against everything else you need, and the best welding gloves for beginners is the other purchase you will make in the same week.