Angles on angle grinders

December 21, 2011 8:11 AM

What to look for when buying an angle grinder?

A friend spent some time WOOFing in Australia, and said people there used angle grinders as a common basic tool for many kinds of jobs. I want to get him one for his birthday (today - last minute idea) but it's a tool I've never used so suggestions would be great. My friend works mostly with wood, cabinet-making, but will soon be building a house.

Thanks for any ideas.

posted by anadem to home & garden (13 answers total)

Wattage, speed and disc diameter are the main variables with an angle grider. Typically, the larger each of these, the bigger the job it can handle.

Fairly good names are Dewalt, Hitachi, Makita or Bosch.

There's not much to an angle grinder. It's basically a big motor with a handle.
posted by le morte de bea arthur at 8:20 AM on December 21, 2011

(I'm sure there are other US-specific models that are good too).
posted by le morte de bea arthur at 8:22 AM on December 21, 2011

Angle grinders are largely distinguished by two things: quality of the bearings / rotating parts (lifespan, vibration, and noise) and wasted weight (how long you can hold it). As a general rule, you get what you pay for. I can kill a $15 Harbor Freight grinder in about six months. I was given an old-school Milwaukee that's survived years and years of hard use.

If he doesn't have a grinder yet, go for the standard 4.5" size. Stay away from the cheap piles of junk if you can (DeWalt, Craftsman, I'm looking at you). Stay away from battery-powered and stick to corded. (Cordless is nice for a very, very small number of applications; in 95% of cases you need lots and lots of runtime.) If you can afford Milwaukee/IR/other high-end, great: it'll last him a lifetime. Since you don't even know how much he'll use it, just go for something mid-tier (Makita) from your local home improvement store.
posted by introp at 8:26 AM on December 21, 2011 [1 favorite]

(Oh, and don't worry about getting a "variable speed" model. It didn't exist for 30 years and no one missed it. It's a new feature for the up-sell and does nothing for you in the vast majority of cases.)
posted by introp at 8:30 AM on December 21, 2011

Strangely I have had good luck with the 4.5" dewalt corded grinders. We used them at the arts centre I used to work at and had no real problems.
Big thing to check for is that the bearings/gearbox are dust sealed. Cheaper ones omit the rubber gasket that keeps grit from getting into the angle gear, this causes them to get chewed up right quick. Other than that they all are pretty similar.
You might also want to pick him up a sanding attachment. Its a little rubber disk that you can clamp sanding pads to and mount them on the grinder. Allows you to sand wood in a hurry for rough shaping.
posted by Pink Fuzzy Bunny at 8:46 AM on December 21, 2011

I have two of the Makita 4" angle grinders (I was given them years ago in the hopes that we'd use them in a Power Tool Drag Races entry, and we never got to that). As others have recommended, get the 4½", if only because they work better with the sanding disks (an angle grinder with a sanding disk is my new favorite tool).
posted by straw at 9:01 AM on December 21, 2011

4.5", doesn't need to be huge power b/c those are too large/heavy to handle easily. Variable speed is a waste.

You want a paddle switch, preferably with a lock-on slider.

The guard should be adjustable w/o tools.

Definitely corded.

The idea is you want something that's small and convenient, otherwise it's tiring to use or requires two hands.
posted by jpeacock at 9:40 AM on December 21, 2011

4 1/2" Makita and you are good to go.
posted by WinnipegDragon at 10:18 AM on December 21, 2011 [1 favorite]

Ah, the gateway drug to metal working.

I've had a Makita for 15 years that has just refused to die. They're nice and not particularly expensive. I wouldn't spend a lot on an angle grinder, because they get used really hard at times.

Angle grinder + cutoff wheel is never the right tool for the job, but sometimes it's the only tool for a job. The cutoff wheel in particular is my go-to tool when all else fails. I cut an entire cars in half this summer with nothing but a sawzall and an angle grinder.
posted by pjaust at 10:54 AM on December 21, 2011

Oh god, third'ing the 4.5" flap sanding discs. If you do any kind of welding, metal clean-up, or metal painting they're the bees' knees. Angle grinder + flap sander disc for rough cleanup and an air grinder + roloc disc for fine work. You'll never buy a box of scotch-brite pads again.
posted by introp at 11:51 AM on December 21, 2011

My father-in-law gave me a cheapo from Harbor Freight (or something similar) and I killed it by the second time I used it. Damn thing had such shitty bearings that it basically wobbled itself to death - I was afraid it was going to explode in my hands. So yeah, don't go too expensive but sure as heck avoid the real chap ones!
posted by caution live frogs at 12:59 PM on December 21, 2011

As a construction worker with OSHA training I can't recommend enough a face shield for any grinding work. I've seen the accident photos when the disks blow apart at full speed. (It can be fatal.)
posted by princelyfox at 1:05 PM on December 21, 2011 [1 favorite]

Thanks for all the excellent info. The store has a special on Bosch 4.5" so that's what he's getting. The sanding and other extras can be stocking-stuffers.
posted by anadem at 1:19 PM on December 21, 2011