Thoughts on angle grinders?

[FleetMech]

Who does a lot of fabrication here?

I'm a lead fleet mechanic for a large construction company. While we typically do a good amount of fabrication, this new year we have been tasked to keep some older equipment alive for longer due to budget constraints. This means a lot more fabrication.

We have been using Milwaukee M18 4-1/2" grinders for some time. Always done the job, but now we're really doing some grinding.

I'm tasked with getting the crew some grinders so I am wondering what the guys who really use grinders suggest?

We recently smoked two older, corded grinders, a Bosch and Dewalt, both 4-1/2". These were both old shop tools that served their turns so I can't complain about them. I pretty much never use corded tools over battery, but I am wondering if an angle grinder is one of those where plugging it in still makes sense?

The problem with the Milwaukee is the batteries just don't last long enough. The 2ah batteries aren't even worth putting on, the 5ah are decent but still require frequent replacement, and 8ah do the job for long enough but are heavy as heck.

What's the hive think? Am I missing something with cordless? If we should buy corded tools, any suggestions? We have always gotten by with 4-1/2", but is 7" or bigger the way to go for larger tasks?

Thanks in advance!

 

[whateg01]

For short jobs, cordless is ok but as you've found, they eat batteries on long jobs. I prefer corded for long grinding sessions. If you want fast material removal and the ability to lean into it, a 7" grinder can really eat. But you also will wear out your arms faster, ime. A 5" is a good size for me, especially if I'm going to have to grind while on my back.

 

[The Cobbler]

I do not own a battery grinder. I have probably 8 or 10 corded ones.
A fellow I watch on you tube that repairs power tools seems to get a lot more battery grinders that are fairly new than corded ones . often the battery units are not repairable while the corded ones often are .

 

[fourjeepin]

Primarily corded for me. I have an older Milwaukee (great), a pair of Ridgid (meh, but they were cheap and came from the hot deals), and a porter cable (really good, and also from hot deals). Oh and a brushless Ridgid. I grab it for quick jobs or ones that are in the yard and pulling an ext cord is a pain.

 

[u2slow]

Corded here too. Including a big 7" (9" frame actually) and it really eats for big jobs.

i have a battery one that is used for quick/small jobs. Thats it.

 

[Dig Doug]

I have both m 18 and corded

for quick hits M18

for material removal corded
make sure they are a high amp grinder 13-15 amp

look at switching on /off there are a few different styles not sure what’s more comfortable - personal preference
paddle, trigger, on /off slide

pic a flavor or color

my current favorite is metabo I have a 4.5 and 7 inch for concrete grinding, I’ll use these for long periods & they are work horses but expensive. I haven’t tried these on metal

also have a few Milwaukee and dewalt for metal working


also helps to blow out the inside after heavy use they get dirty

 

[Kurt4440]

I have a few corded Metabo grinders that are all about 10 years old and made in Germany. They are my best grinders. I also have an assortment of Hitachi, Makita, Bosh, DeWalt and Milwaukee corded grinders.
I don't know about current production, but, the Metabo would be at the top of my list followed by Makita.

Good luck and stay safe, the corded grinders have more power and can be tough to handle, especially when you get into the larger size grinders.

 

[seber]

I have seven corded and one M18. I quickly learned the battery unit is not suitable for anything I do. Of all the ones I have and have had, the Metabo and Hilti are in a league above.

 

[tyyost]

I have the Milwaukee Fuel grinder, and it needs at least a 6.0 battery to be useful. I also have several other corded grinders, including Metabo, Milwaukee, Bosch, and others. For a Fab shop with access to 120V power I’d be looking at the upper end Metabo or Bosch grinders with the vibration reduction and automatic electronic speed adjustments. If consumables are not a concern I’d also look at 5-6“ grinders as the extra rim speed over 4 1/2 as well as the extra grinding surface makes them a bit more versatile. And they run 4.5” if needed.

 

[OccupantRJ]

I have one cordless DeWalt grinder and 9 corded ones of various brands. The cordless gets reserved for quick remote outside work. I have cord reels in the shop for convenience when using the corded, and sometimes use a multi outlet electrical adapter on the cord reel ends when I have several grinders in use. If you want cord reels, get 12-15 amp models as the round drum types are usually good for 10 amps with not so great wiper contacts that tend to fail.

 

[dnschmidt]

Cordless if portability is required, like cutting off a muffler. Corded for everything else. This use to be an open an shut case with Metabo the clear winner but now that KKR is doing it's best to destroy the brand my second choice would be Makita for corded and Milwaukee for cordless using the Forge batteries. Makita's batteries are beyond expensive, they're ridiculous, whereas you can always get some sort of a deal on Milwaukee's batteries.

 

[MJD1]

Corded metabo is the best I've used. I prefer a 6" as it's not a lot bigger than a 4-1/2" but much better performance. Cutting with a disc, the 6" gives a much better cutting depth and discs aren't much more expensive. As for cordless, the 20v DeWalt is fine for light duty work.

 

[GaryM909]

I used angle grinders for my whole career. 7-9" are fast but heavy and awkward. I still have a couple buried somewhere that I use once every couple years. 4½ grinders are for light duty and the discs wear out too fast. I have a couple of those too that never get used.
My favourite are corded Makita and Dewalt 6" grinders as well as two cordless 6" Dewalt grinders with three 9 ah batteries. When you wear the 6" discs down you can put them on the 4½ grinders.
Just mucking in my garage these days I don't preplan when I am going to use a grinder so my batteries aren't usually fully charged when I start a project. The corded ones are always ready to use.

 

[Rusted Nut]

I have an M18 Milwaukee 4 1/2”, great for small quick stuff. I had to use it in area with no power to cut up some thick channel, batteries kept overheating. Fab work - corded every time. I just retired from commercial construction, Bosch grinders just keep going.

 

[NUTTSGT]

If you want corded and have an issue with crews literally abusing them, maybe it's time to go quantity over quality.
Go to HF and buy like a half dozen of them. . . Give 6 months and see how they hold up. You might find a 6 month rotation of grinders makes the most sense . . . Time vs money.....

 

[dnschmidt]

The six inch variable speed Makita is hard to beat in corded. I agree that six inch is the perfect size and if you can't swing that 5" isn't too bad either. I have little use for 4 1/2 inch grinders particularly with cut off wheels as they wear out too fast. Six inch for cutting and 5" for grinding seems about perfect to me. Having more grinders than I can count (minimum of 12 but who really knows?) this is my conclusion after forty years of using grinders.

 

[AEAdam]

I feel like Bosch is the OG of angle grinders. My take is the same as others here. I love my 18v, but wouldn't be happy if that was my only.

 

[loganb]

For serious grinding, corded made in Germany Metabo...don't buy the Metabo HPT available in big box ...not the same stuff. Buy the most expensive model you can, pair it with quality consumables and the shop will fight over it

 

[finn]

I have a cordless Dewalt Flexvolt Dewalt, and another six or eigh, and maybe more of various brands, from a $10.00 Orange Harbor freight to a couple of high amp Metabo. They all have their place, I typically use the smal, light Bosch, Makita, or Milwaukee for most work. The Porter Cable that were on sale a year or two ago for $20 have flap discs and wire wheels.

I’m not a heavy user, so they all work well for me. I’m not a brand loyalist. The only failures I have had are when the plastic handle of the HF exploded spontaneously on the HF at low temperatures (frequent failure on other HF products), and I can’t get a switch for an old Skil that became obsolete during a brand ownership change (one of many).

 

[rsanter]

I have Dewalt 20v and corded.
my friend has the Milwaukee

I love the cordless but they eat batteries. So they are good for short/fast jobs and that all.

for everything else I get the corded ones out

 

[Sumboodie]

I have 5 or 6 M18 and a couple 120v Borsch slim line.

The cordless ones work fine for 95% of what I'm doing. Have one for cut off, one for grinding, one for flap disc, 2 for different wire wheels and 1 for paint/rust remover disk. And a spare I brought to work.

 

[FleetMech]

I really appreciate the responses! A lot of good info here. I'm glad I asked the question.

It sounds like it is pretty much agreed that corded is the way to go for significant grinding. That's the route I will likely go. Also seems 6" is probably the sweet spot. I have never owned a Metabo tool, but that might have to change...

Again thanks for the responses. Keep them coming. Tremendous knowledge in this forum.

 

[AEAdam]

I have 5 or 6 M18 and a couple 120v Borsch slim line.

The cordless ones work fine for 95% of what I'm doing. Have one for cut off, one for grinding, one for flap disc, 2 for different wire wheels and 1 for paint/rust remover disk. And a spare I brought to work.

I think this is really interesting and hope everybody is picking up on this thread.

I've noticed in my travels, fabrication guys, machine shops, metal workers of all kinds, seem to have multiple angle grinders each fitted with a different attachment. I only have 2 and they both have different attachments always. I keep a cut off wheel on my 18V. I can usually cut whatever I need and more on a single charge. Flap wheel, I could spend an hour with on some jobs. The flap wheel is on the corded grinder.

I also have a little wet grinder with concrete disks for it that I use more than I thought I would. Bought it for one (important) job off amazon and have used it quite a bit since.

 

[Farmall450]

For a Fab shop with access to 120V power I’d be looking at the upper end Metabo or Bosch grinders with the vibration reduction and automatic electronic speed adjustments. If consumables are not a concern I’d also look at 5-6“ grinders as the extra rim speed over 4 1/2 as well as the extra grinding surface makes them a bit more versatile. And they run 4.5” if needed.

I bought a 5" Fein from the hot deals here like 10-12 years ago for exactly that. Not sure if they're still awesome, but that's one oddball brand that makes a really good grinder.

 

[rooster59]

Old German Metabo are great, made in Japan industrial is great stuff. They are heavy. Cordless is good for light quick stuff. You need maybe some 4.5” and 7” industrial grade corded with More Power No substitute for a big powerful corded grinder if that is what you need. 7” grinder is maybe 13 pounds with wheel. Look up the rpm specs and understand which guard go with which type wheels you will be using. Safety equipment PPE is a must. Since you’re industrial see who does local repairs to what brands. The environment can be pretty brutal, grinding dust, heat, drops onto concrete. Replace switches, brushes, cords, plugs. If nobody local services xxxx, then I wouldn’t buy xxxx. One good source for grinders is welding supply.

 

[JuncleJohn]

We only have corded at work. One each, 4-1/2” Milwaukee and a DEWALT (also a couple 7 inchers that live in the cabinet). The Milwaukee has lasted forever because no hardly uses it. The DEWALT is more popular because it just fits the hands better.

I just bought 2 more Dewalt’s this week. DWE402 is the model number and cost $100 each.

Same as the one in my home shop.

John

 

[Firebrick43]

The German corded metabo’s are the best bar none

 

[JDN]

In my fab shop we have dewalt 20v 4.5" and 60v 6" along with milwaukee 18v. The milwaukee collects dust, nobody likes the way it feels or it's lack of power. On the corded side dewalt dwe402's seem to hold up well for a sub $100 grinder. German metabos are great but expensive htp versions are not.

 

[Farmall450]

This just came through slick deals:



I've been looking for a designated BL flapper machine, so I ordered another 20v one.

 

[neophyte]

I have no clue if the manuals still list “service intervals” ie. , the hours of operation the tool should be used for before being pulled from service for overhaul, regreasing, new brushes, etc., but the service intervals on the older FLEX brand grinders before Chervon bought FLEX were around 10,000 hours.
Those grinders had safety electronics, (constant speed control, automatic shut off, etc.), but were otherwise simple and without variable speed, and also just used a slide switch.
The bodies were a bit large in diameter.
I believe those older cordless tools may still be in production, and specialty abrasive suppliers still seem to sell the tools, but it’s not something one can just buy at Lowes.
(These are the red and black German made grinders that usually cost $200+/-).
Fein still manufactures angle grinders in Germany, and I presume these are still made to Industrial specs, but would be similar in price yo the FLEX brand German grinders.
The ergonomics would likely be better.
The same goes for Metabo.
Corded grinders from Bosch might be similar quality, or at least they used to be.
The same might go for the more expensive old school Makita designs, but there seem to be more complaints about quality nowadays.
Some users swear by Hilti, although Hilti grinders are now made in China. The rumor used to be that the Hilti grinders were a custom Hilti housing using Bosch internals. (I have no clue if this is/was true, although I recall dome of the grinders being made in Germany, do it would seem possibke, since that was were the Bosch angle grinders were made when made in Europe. Other older Hilti tools were sometimes also made by Metabo).


For “Industrial Use” there are also “High Frequency” grinders, that require adapters to up the electric frequency to somewhere between 200-400Hz.
My understanding is the motors don’t have brushes, and have high service life, but they are also fairly expensive, since they are mostly just made for actual industrial use.
Fein is, or was, a manufacturer.
Bosch was as well, I think maybe inheriting the product line after Purchasing Stanley’s older power tool division.
Usually the high frequency tools don’t appear in manufacturers regular tool catalogs, and need to be purchased thru specialty sources.

One of the other comments was just to buy the cheap corded grinders from Harbor Freight, and see if those work out.
This is probably not a bad suggestion.
A simpler grinder is less likely to fail due to complex components breaking, and if the grinder dies, just try taking it back for warrantee it, or toss it in the trash, since you’re not going to be out much money anyway.
Usually, electronics (variable speed etc.) are going to die first, then maybe brushes, and cords getting accidentally cut.
Power tool cord can be purchased in large reels, as can industrial spec plugs, if this becomes an issue.
Electron boards are usually expensive enough that they may only be worth replacing on high end grinders.
Switches can also fail, but those are usually available from multiple manufacturers.

For ergonomics, the skinnier grinders that use brushless motors are better, but those motors rely on fancier electronics, and I don’t know how well those will hold up.

 

[MongoTA]

If grinding a lot or continuous for several minutes I prefer corded, even though the cord can get in the way. I have a mix of DW and MK corded grinders, maybe 8 total. Only maintenance I've ever had to do was replace brushes, and that's a one minute, one dollar repair. That's on the older tools. Several years ago I had too much free time and I lubed them.

I have DW cordless. While they run great, I use them for convenience jobs; a quick hit job or if I'm not near an outlet, outside or up on a ladder, for example. I'll almost always use a larger battery on it, 6Ah or 9Ah, etc. I'll sometimes use the cordless knowing I'll kill one or two batteries. Depends on the day and the project. But I'd prefer to not run a full battery down to nothing in one go.

 

[kngelv]

I work in an industrial setting. For cordless we use Milwaukee with Forge batteries. They last much longer than the high output ones. For corded it's real German made Metabo's all day/every day. At home I have a couple of corded Fein I scored on some price glitch and they are just as good as the Metabo but not as easy to get here in the States.

James

 

[dutchgray]

For employees to use in a shop, corded, good ones like German made Metabo or Fein or the higher end Makita ones.
If your employees are the types that push tools really hard all the time than going cheap and keeping a bunch of new ones in stock may work out cheaper over all, Hitachi used to make a good and cheap 4.5" that seemed to last well, I still have two left but it was fairly low power.

 

[AEAdam]

HATE TO BRING THIS UP:
For guys doing a lot of metal work, which can be pretty nasty and harmful to tools, does it make sense to buy 4 or 5 HF angle grinders?

I bought a HF recip saw many years ago. It worked fine, except it was loud and sounded like it was about to seize up. Like the gear lubricant was play sand. That was quite a long time ago. I feel as tho an angle grinder is a pretty simple tool. I just checked. Has anyone had experience with the $30 models?

That said, I have this one. It's only $80. So these aren't crazy expensive

 

[zimman]

This is fabrication. LOL. You know how many batteries would be required to do this?
Base your decision on time with a grinder in your hand. For quick cleanup and easy mods, battery is fine.
Major fabrication and overhaul, go corded. My Craftsman grinder has built 13 chassis. Still going and a bit wobbly. LMAO
Zim

 

[Steve_P]

I have some 5" German made Metabo and love them- the only issue for a DIYer is that there aren't a lot of "off brand" 5" consumables, so unless something has changed since the last time I looked, the 5" stuff is very expensive as opposed to 4.5" which is much more common. Since this is for work, it's irrelevant as the company will buy it.

It does sound like you should also have some 6-7" grinders to speed things up on jobs with lots of material removal required, but a 4.5-5" is nice for quick jobs since they're lighter. I have an ancient 7" grinder from my dad that I never use since it weighs a ton and I'm not working on heavy equipment.

 

[whateg01]

I have some 5" German made Metabo and love them- the only issue for a DIYer is that there aren't a lot of "off brand" 5" consumables, so unless something has changed since the last time I looked, the 5" stuff is very expensive as opposed to 4.5" which is much more common. Since this is for work, it's irrelevant as the company will buy it.

It does sound like you should also have some 6-7" grinders to speed things up on jobs with lots of material removal required, but a 4.5-5" is nice for quick jobs since they're lighter. I have an ancient 7" grinder from my dad that I never use since it weighs a ton and I'm not working on heavy equipment.

I don't know where you shop, but there seems to be plenty of 5" stuff. Besides a 4.5" disc will also fit.

 

[The Cobbler]

seems to be plenty of 5" stuff. Besides a 4.5" disc will also fit.

and when 5" discs get worn down some they work nice on a 4-1/2"

 

[strength_and_power]

It’s almost a stretch to call cordles grinders grinders regardless of the flavor. Polisher or deburring tool may be more accurate. I use a heavier grinder for cutting off wheels and actual grinding discs. For a flap disc or wire wheel, I like smaller grinders that I can hold in one hand and hold my workpiece in the other. Trick Tools had a 2 pack of Fein grinders that other than color were identical to Makitas. Around $110 for the two pack.
If the fab work is in a shop, it may be a good spend for a Metabo. For in the field work, say up on a ladder, probably something cheaper.
Is this sheet metal fab work or thicker structural fab work?

The quality and longevity difference between a $30-40 HF grinder against a $110 grinder is probably a lot greater than a $110 grinder against a $300 Metabo. Drop any off a ladder and all bets are off.

 

[NUTTSGT]

HATE TO BRING THIS UP:
For guys doing a lot of metal work, which can be pretty nasty and harmful to tools, does it make sense to buy 4 or 5 HF angle grinders?

I bought a HF recip saw many years ago. It worked fine, except it was loud and sounded like it was about to seize up. Like the gear lubricant was play sand. That was quite a long time ago. I feel as tho an angle grinder is a pretty simple tool. I just checked. Has anyone had experience with the $30 models?

That said, I have this one. It's only $80. So these aren't crazy expensive

I've got two HF angle grinders, 4.5" & 7", specifically for masonry work like cutting block... they have survived cutting a few hundred block. I would think concrete dust would be worse that grinding metal.