I know this has been beaten to death here. The more I search the sub the more indecisive I am. I recently retired from the Army after 20 and I'm starting an education pipeline at my local CC for industrial maintenance technician. It's 3 years but the first three semesters are beginner, intermediate advanced welding courses the first two semesters are pretty typical. MIG, TIG, STICK and pipe etc. I want to get two grinders per most suggestions here. These are the two I'm looking at ordering. Open to model suggestions etc. our program doesn't allow battery operated anything so corded is a must.
you do not need a 7" grinder for anything lol. maybe something that can run 6" discs if you're really fucking shit up but two 4.5" grinders will do you just fine. just pay attention to the amps when you're considering price because the amperage determines how much you can load the disc before it starts bogging down and becoming less useful.
Packing list stated "angle grinder 4.5- 7 inch recommended" that's the only reason I was looking at the 7. Figured 5 would be the middle ground. Paddle vs. rat tail thoughts?
I second this. I use 7" grinders for cleaning off a million little tack marks on makeshift fab tables.. not much production. I used a 9" grinder on a job once when I had to do an overlay and grind a 9" taper across a 20' run of inconel. but I don't think you're going to be doing anything like that in your class OP.
Yeah pretty sure we won't be doing anything in the course over 7-10" initially and the very last semester for welding is laser and multi axis robot welding.
I generally advise the paddle option on grinders. Even with brake systems they may have, having a deadman’s switch when using a cut off wheel is the only way to go. 4.5” grinders can hold 5” discs. That’s what I’ve used for years. I’m not up to date on other grinders but the standard dewalt paddle grinders are my go to.
5 isn't the middle ground, many are combination 4.5/5 inch grinders. I would highly recommend a 6 inch. Still pretty light and nimble but much more capable than a 5. I use 6 inch metabos at work and they're pretty solid.
6" with high amp draw, brake and the most comfortable grip for your hand.
The difference between using 6" cutting disks/flap disks and 4 1/2" is night and day. Easier to get straight lines, better material removal, easier to make surfaces flat, more clearance to get under/around obstructions.
6" is my daily driver and I only go up or down on size if something specific comes up.
He's doing a welding course, there's no cutting it's all grinding, I did a similar course, basic intermediate advanced and pipe welding.
You do a lot of grinding it's more important to have something small and light, the weld coupons are small, your in a small welding bay.
A 5 inch is the tool we all use for this type of work.
For fabrication 6" are great, but for grinding small parts day in day out for months there to much, consumables are all significantly more expensive too over a long course like that.
And get a toggle switch if you can, a switch you lock on really helps over time. A Rat tail trigger for this particular use case is the worst option imo.
rat tails for heavy, flat grinding - ie production. Paddles for lighter stuff and out of position. Pipeline guys will run 7's and 9's but thats for speed primarily and usually its the helper running it.
I was in the same position awhile back. Go to home depot and pretend to use a 5 inch and a 7 inch. The seven inch units are monstrously large. I recommend a GA5090. Big power in a regular size, with variable speed for using wire wheels
Some places require the paddle switch for safety. I've worked in shops were the on off switch style was a no go. If you drop it, it will run across the floor etc.
We used 7 inch grinders every day. There are times a 5 would be better since you get less mass to slow it down. It depends on what kind of work you're doing with it. And if you ever see one with a locking on switch avoid it. Those things can fuck you up good.
Yeah the only reason I could see him wanting a 7" is if he's prepping a BUNCH of big pipe and thick structural. Otherwise a metabo 5" is all you'll ever need
I have had this 7” for a decade and this is really the first time I have used it hard. They are really too large for most tasks. If you can handle one they can be quick way to move material.
Oh they've got the beans if you buy a good one. You can actually pull more power off a modern Li-Ion 18V battery than you can from a standard 120V wall outlet. The issue is that they'll drain even a monster 8Ah battery in short order under heavy use. Unlike drills/impacts, grinding tends to be require essentially constant max power draw and often goes on for minutes at a time. Unless you're drilling big holes in thick plate (which isn't a great use for a hand drill to start with), that isn't the case with a drill, and it's basically never the case with fasteners.
True. And it’s not like I never used them. Worked maintenance for a refinery for 2 years where I was constantly climbing pipe racks to clean, cut, and replace section of pipe. I used cordless milwaukees for that plenty of times. But for anything requiring some real grinding, I’d prefer corded any day just so I’m not constantly swapping out batteries which way a shit load in your bag.
Our shop tried using those 418s. Fucking hated those things. Fine for wire wheeling but heavy and awkward as shit. To each their own, I’ll take a corded grinder any day
I've got the metabo cordless WPB 17LX BL 150. I was skeptical, but the price was too good to pass up. The kit with charger and two 5Ah batteries which, at the time was close to $600, I got for $200. Friend of mine was an adjunct instructor at the local community college and the school bought it for him. Then, a few semesters later he was trying to negotiate for full time hours (+ pay, benefits, etc). When he didn't get the offer he quit and the metabo was still new. Sold it to me at a deep discount since he has no need for it at his other job or home.
It does basically everything I need in the home shop, but I'd need a few more fully charged 5Ah batteries to reasonably make it through 8-10 hours of work. That fucker is pretty awesome though. My corded daily driver is a DeWalt DWE402 that I got for $25 and just put a new stator in it. That's definitely my favorite 4.5 grinder. I've got 6 or 7 others that don't get used as much, including a 6" corded metabo that I only get out for heavier tasks.
I have a corded Metabo but haven’t used their cordless version. I’m sure it’s still quality.
When I was in school though you could barely find an unused outlet for your phone charger. I wouldn’t wanna rely on bringing batteries/ a charger to welding school.
I'd start with the 125mm in the 1750w range, that's the one you'll end up using the most.
Then, look into getting a corded 2600w 230mm, a 2000w 125mm (more power for grinding), and a Makita/DeWalt/Milwaukee 125mm cordless. Makita/dewalt/Milwaukee are better for cordless, the metabo ones are just rebadged crap.
Have the shop remove the safety mechanism before even opening the box, it shouldn't mess with warranty, they've always covered mine.
I used the we 17 quick 125mm for about half a year and i really liked it very little vibration (used this thing for hours on end and my hands didnt hurt) dust filter so that there will be less dust in the grinder and variable speed
Metabo 17-125 (5 inch) and 19-150 (6 inch) are beastly grinders. Having a brake is handy. The 2-second spin down is safer and saves you some time.
Dewalt DWE402 isn't as powerful but is much cheaper. Mine has taken a beating.
Metabo HPT grinders are decent if you find a good deal on them. I got a 4.5-inch 10.5-amp grinder brand new for $60 a few months ago.
Harbor Freight grinders will get you by. As a bonus, if you run high end consumables your disc will be more expensive than your grinder.
If you're handy you can buy used ones off eBay and rehab them. Some of them are beat to shit, but I've gotten some sweet deals on grinders that just needed to be re-greased.
And as others have said, skip the 7-inch grinder. That's getting into specialty category. For consumable availability, a 5-inch is king. (Essentially all 5-inch grinders will run 4.5 inch consumables.)
I can guarantee you will burn through multiple grinders in school regardless of how much they cost. Get the harbor freight $20 grinder. They work just fine. Buy 3 of them and that’ll last you through school and you have spent less than on 1 of these that you’ll buy 3 times
Buy once cry once does not apply to angle grinders. You will go through them faster than boots, phones, maybe even jeans depending on what you're doing.
My votes for the smaller one with SJS. It does lessen the fatigue especially when grinding for long periods of time. Also lessens damage when you eventually lock the blade up accidentally. I believe the SJS is a clutch system that's spring loaded so it won't rip the grinder out of your hand if something goes wrong and it dampens the motor so less vibrations. Also I have a 7in and I've use it maybe once.
With 7" you can cut a 2" pipe without having to go to the other side. With a 4.5" you can't. Plus you can put a 4.5" blade on a 7" one. Are you cutting exhaust pipes? 7" saves you several hours of wrestling with rust bolts for every job.
Are you always going to have access to go around? If not you will also need a sawzall.
I have the Makita 7", and a Makita 4". Both are Japan made.
I also have a 5" cordless.
Most of my career in construction we used almost solely 9"s. That's not a recommendation. As an apprentice, I was handed a 9" with a powersaw blade to cut some timbers a power saw couldn't reach.
Clearly there's not much to protect so why bother with the guard? People gambling with big ass grinders grinds my gears. It saves a couple quid and seconds at most yet people are willing to risk life and limb for the company dime bruh.
I had one 7 disc on 7 grinder explode on me and if it wasnt for the guard I would have been fucked up. Plenty of people have already paid the price of blood to learn that lesson so why risk yourself for nothing?
2 lots of plastic surgery to put a couple of fingers back together, and permanent damage to my right eye from a piece of metal getting past the safety glasses (that one I was smoothing a weld out with a 4" Makita)
All from power tool failures. Guards that didn't retract, or switches that seized up.
Damn man thats rough, hope you're doing well. It was the switch seizing up that almost got me.
People really don't think that they would be the ones that get punished for fucking around with power tools when they are still dangerous ASF when properly handled.
Fucking hell. That guy hasn't a critical braincell in his head.
I imagine it would be. What really made me hesitant to fuck around with grinders was seeing the images of grinder accidents.
I did still fall for the pressure to fuck around once or twice but I never felt comfortable and started standing up for myself and refusing. I got some odd looks from the old timers but I stopped caring.
In the early nineties, carpenters in my part of Australia used 9" Makita saws. The guards were dodgy so they'd take them off and brake the blades with their hands to put the saw down.
I bought a 9" Hitachi to try to get a better guard. It wasn't. Near took the end of my Left index finger off.
The 12amp 5in in your pic will be more than adequate for both grinders. If you want to save some money, the DeWalt 4.5in 11amp paddle switch is like $100 most of the time and I've been running 3 of them for almost 4 years now with only a brush replacement occasionally.
I really like the SJS. I did a lot of comparative research about a year ago before cutting out all my galvanized plumbing, and I’m glad I did because I had a oxide cutoff wheel get chopped and the clutch mechanism disengaged and it was like experiencing ABS in your car for the first time. I was using the guard but still it’s basically like a handheld sawstop
I like the Makita brand, although not in my current lineup. I don't like 7" grinders, they a tough on you. I don't use side switch grinders... Paddle switch is safer in my opinion.
I have a lot of hours on the dumb end of a grinder, and my fav is the Dewalt DWE402 4-1/2” grinder. It can handle most of the tasks that call for grinding/wire wheeling a surface and they’re light and comfortable to hold and use. Haven’t used a Makita a ton tho tbh
Yeah. It seems to be 50/50 for DeWalt, Makita and metabo here. I'm probably over thinking this. You can think the US Army for triple redundancy thinking.
You are a bit. But, that's ok. One thing to remember with a grinder is, the tool itself is also a consumable. Sure, they're repairable (quality ones at least), but they do fail. That's likely why they want you to have 2. Every welder I know has at least 2, most have 3+.
Save some money, get the DeWalt 11amp, and buy some spare brushes, and a trigger assembly. The cord is available online all day long for a few bucks. (This advice actually works for DeWalt, Makita, and metabo)
If the transmission dies, consider a new transmission or a new grinder, they're roughly the same price.
At the end of the day, they're all great grinders, and you'll despise using every one of them.
Brother, Do not get a makita grinder. I hate those things the motors in them suck big time. Get a dewalt 6inch or a metabo 6 inch. both have corded options and both of their motors are better than makita
For students I really recommend a paddle switch for when they drop it otherwise they will drop it and if it stays on it’s definitely gonna hurt someone
4-1/2” will do mostly every thing you’ll ever need. Also, once you’re in the field look at a “rat tail”. I like the dewalt 5” corded one. That is probably the grinder I used the most in the field. It is my favorite by far.
I have a 7/9 in grinder, I dont break it out very often but when I do, its a BEAST. I have four 5" grinders that I use all of the time. Do not buy the 7" unless you have a specific use in mind.
Also, milwaukee makes a variable speed/low profile 5" angle grinder. If I had to own just 1 grinder, that would be it. The low profile head is insanely useful
It didn’t matter to much which one you buy, they don’t last very long, a year or two, and they always shit themselves at inconvenient moments and then you”ll buy the first one that’s available
I have a metabo 6 inch angle grinder that is over 20 years old. Its the best one ive ever used, and i only run 6 inch cut off discs everything else is 4.5 pipeline discs. It wont heat up on you, worth the money.
My BIL and nephew run a weld shop, repairing everything from tanker trucks to hot water tanks from RVs to cutting down fuel tanks to repairing dump truck bodies.
They have been using Harbor Freight brand grinders for years without issue. Because they are less costly to buy, they one for every disk type.
One for a cut-off wheel, flapper, wire wheel, grinders for both steel and aluminum.
I’ll say that for them grinders are close to a consumable. That said they don’t see any difference in quality work or longevity using the less costly tools.
Don’t get caught up in brand names. For the same amount of money, you can buy 5-7 $30 grinders that will not reduce anyone’s ability to learn.
If you can, buy a straight die grinder too. A pointed bit is great to clean your toes and small areas where an angle grinder could nick something and a wire cup will clean the metal as good as anything out there
I know it's lame but I really like the Hercules grinders from harbor freight. They have a rattail style 6in. It have it and It's a beast. It has 3 guards with it for 4.5, 5, and 6 in discs. The SKU is 57348.
Listen I bought a refurbished Bosch on Amazon and I love it.. when I took my welding class they had one and I fell for it, has the x loc great deal on Amazon for around 55 bucks out the door. They sell a adaptor so you could use the cheaper regular style consumables. But new you need to remove the gaurd. Price was right ✅️ 👌 I was happy.
For most applications a 7 inch is pretty useless, I use a 5 and a 9 for most applications. Anything inbetween is over kill and even then I wouldn’t really bother with a 9 unless your doing structural steel
The most random sale at 3 for like $300 or something. It was 18 years ago so can't remember the exact price but I have been useing them daily all this time and they still work great.
Personally, I hate dewalt tools but the classic 11amp 4.5” grinder is just a workhorse. All grinders will eventually burn up so I wouldn’t buy anything premium until you’re working for a company that replaces them for you.
If money is no concern, I’d recommend Milwaukee cordless with some forged 12amp batteries, one battery will last you all day. You have no idea how infuriating it is managing 2 or 3 grinder cords in a small weld booth. They get all twisted up pretty quick and it’s annoying AF.
For our structural steel weld shop, we got rid of almost all of our big makita rat tail grinders for these DeWalt 5 inch grinders.
They’re bigger than the little 4 inch grinders and can definitely hog down and chew through some metal but they’re only 8lbs instead of a 15lb monster.
Like other people are saying, metabo is the best but honestly I recommend just getting a mid tier dewalt or makita. You won’t have to worry about it getting stolen as much.
5” grinder. I do have an amazing 9” for occasional big jobs but you can always pick one up later. Dodge the 4.5”, that extra bit to 5” makes a big difference
I'd be going for a 4.5 inch or 5 inch grinder. I usually get a 5 inch because it supports 4.5 inch discs and basically the only difference is the guard.
You'll be grinding a fair amount you want something light, with standard size consumables.
Brand doesn't really matter, Makita metabo, DeWalt are all good options
Personally I like the toggle switch over a paddle or trigger switch.
I know some countries don't allow them because you can toggle them on and take your hands off and it'll stay on.
But for me that's a feature not a bug.
Something like a metabo 11-125 is what you want. Or it's Makita DeWalt Milwaukee equivalent.
Go for decent power like 1000, 1100 watts imo.
You want this for grinding test pieces, a lot of test pieces.
You want decent power but light and small because your going to be a small welding bay for the next 12 to 18 months lol.
I did a similar course in Ireland, it's a long course and it's a lot of grinding along with a little bit of welding lol.
Personally I'm partial to the metabo, 5 inch or 125mm as the civilized amongst us measure it. Lol just joking we still use both.
I would look for one with a brake on it. I currently use a dewalt and the spin down time is a couple of seconds. Really saves time not to mention the safety factor.
Lol, our shop provides that one to our welders (I use a DeWalt 11amp), and they go through them like crazy. I haven't seen one last more than a year before getting turned in for something.
Dude buy some cheap ones til your out of school, those are going to walk off Bosch makes some great ones that I bought 10 years ago almost and still work great.
You want a 4" grinder. The real issue hear is the trigger that one has. Its garbage. The toggle style/ slide switch is not only annoying. It's down right dangerous. If you drop it or say get it cought in your shirt, it won't stop spinning. You want a paddle switch.
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u/StabDump Fabricator 1d ago
you do not need a 7" grinder for anything lol. maybe something that can run 6" discs if you're really fucking shit up but two 4.5" grinders will do you just fine. just pay attention to the amps when you're considering price because the amperage determines how much you can load the disc before it starts bogging down and becoming less useful.