Where this grinder sits
I bought into Makita LXT years ago and Joel’s never let me forget it, so take this with the appropriate grain of salt: the DGA504Z is the 125mm grinder I’d put in your hand if you’re on the same platform. It isn’t the most powerful skin Makita sells. I’d still steer you here, because at home the safety gear and a sensible price matter more than raw grunt.
Here’s where it sits in the range. It’s the brushless slide-switch model in the middle of Makita’s 18V 125mm grinders — above the brushed entry tools that wear out faster, below the dearer paddle-switch and wireless-start versions you mostly don’t need at home. The middle is usually where I tell people to shop: you get the better motor and the safety electronics without paying for tricks that end up living in a drawer.
The dull bit first, because it’s worth real money. Makita’s warranty runs five years on the skin, but only if you register the tool at MyMakita within 30 days of buying it; leave it unregistered and you’re back to three. One catch on top: that cover only attaches to genuine Australian stock bought through an authorised dealer, so a “plain packaging” grey-import listing can carry no Makita warranty at all — check who’s selling before you bank on it. Registering takes five minutes, and I do it the night a tool lands on the bench — the version of me who forgets is the same one who’ll need the cover 18 months later.
How much grinding power does it have?
The motor is brushless and spins the disc at up to 8,500 rpm — revolutions per minute, how fast the disc turns. Brushless means there are no carbon brushes, the little blocks that rub on the spinning part in older motors and slowly wear down and bleed off power. So it runs cooler, gets more work out of each charge, and lasts years longer than the brushed motors in cheaper grinders. On a tool that lives in dust and sparks, that sealed-up design earns its keep.
Speed on its own doesn’t cut anything, though — what matters is whether the tool holds that speed when you lean into a cut. This one has what Makita calls Automatic Torque Drive: when the disc starts to bog down in thick material, the tool feeds it more torque to keep it spinning rather than stalling. Torque is twisting force, the grunt behind the disc. An 18V grinder won’t match a big corded 9-inch for sheer pace through heavy steel, and I won’t pretend it does. But for cutting tek screws flush, slicing through 100mm posts, grinding welds back and cleaning up rust, it handles the jobs a home project throws at it without bogging down. A grinder earned its keep right through our Gippsland build doing exactly that kind of work, and a cordless skin like this one covers it without trailing a lead across the yard.
How does it keep you out of trouble?
This is the part that earns the score, and it’s why I’d hand this grinder to someone picking one up for the first time. A grinder is the most dangerous tool most of us own. A 125mm disc spinning at 8,500 rpm has no interest in your day, and the failure mode that hurts people is kickback — the disc snags in the cut and the whole tool jerks back hard towards you.
The DGA504Z works against that on a few fronts. Kickback detection uses sensors to spot the sudden jam and cut the power before the tool can twist out of your hands. Soft start winds the disc up to speed over a moment instead of lurching the second you hit the switch, so it isn’t fighting to leap out of your grip on startup. Anti-restart stops the grinder powering straight back up after the battery’s been pulled or the tool’s stalled — you have to switch it off and on again on purpose. None of that replaces the guard, the right disc and a pair of safety glasses. SafeWork’s line on keeping the guard on and the disc size matched to the grinder is the rule that keeps fingers attached. But the electronics are a real layer of protection a basic grinder doesn’t give you.
What’s it like to use?
It’s a slide-switch grinder, and that’s the first thing to weigh up. The switch sits on top of the body and you push it forward to lock it on, so you’re not pinning a trigger down for the whole cut — kinder on your hand over a long job. The flip side is that the tool keeps running if you drop it, where a paddle-switch grinder cuts out the moment your hand comes off. The anti-restart and kickback detection soften that, but it’s the one ergonomic trade-off to know before you buy.
At 2.0kg as a skin it’s no featherweight, and the battery adds more on top. A grinder is a two-handed tool anyway, so wind the side handle in — it screws into either side of the head for left or right-handers. The body runs 362mm nose to tail. The spindle, the threaded shaft the disc bolts onto, is an M14 thread, the common size for 125mm grinders, so the discs that fit it are in every hardware aisle and you’re never stuck hunting an odd fitting. Makita’s XPT seals the motor against dust and moisture, which on a tool that works inside its own cloud of grinding dust is a big part of why one lasts and another dies young.
What does buying it commit you to?
The same thing every cordless tool does — a platform. Buying the DGA504Z buys you into Makita LXT, the 18V battery shared by north of 250 other Makita tools. That’s the real case for paying Makita money over a budget brand: the expensive part is the battery, and once you own a couple, every tool you add after costs you only the skin. Joel runs Ryobi and we’ve argued the platform question into the ground — I’ve set out the battery sums, the warranties and where each one earns its keep in our battery platform comparison, and it’s the first thing to read if you haven’t committed to a side.
If you’ve already got the Makita DHP484 drill or anything else on LXT, this grinder slots straight in on the same batteries. And a grinder is one of those tools you don’t think you need until the first rusted-solid bolt, or a cut that’s gone wrong and has to be ground back.
Should you buy it?
Buy it if you’re on Makita LXT and you want a grinder for the cutting, grinding and rust-stripping a home project keeps throwing up, with safety electronics that lower the odds of the tool hurting you. The 8.5 is me being straight: the brushless motor and the kickback detection are the best of it, while the skin-only pricing, the slide switch and the weight are the trade-offs you take with it.
If you only ever need a grinder for one quick job — cutting a single seized bolt off — a cheap corded one will do that for a fraction of the spend, and I’d point you there rather than sell you more tool than you need. But if you’re building or renovating on the Makita platform and want a grinder you’ll still be reaching for in a decade, this is the one I’d buy. I’ve bought enough LXT to mean it.
Specifications
- Voltage
- 18V (LXT platform)
- Disc size
- 125mm (5 inch)
- No-load speed
- 8,500 rpm (revolutions per minute)
- Spindle thread
- M14
- Motor
- Brushless
- Switch
- Slide switch
- Safety
- Kickback detection, anti-restart, soft start, current limiter
- Length
- 362mm
- Weight
- 2.0kg (skin, no battery)
- Warranty
- 5 years (registered)
