cheap grinders

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I would prefer this thread not to degrade into the usual mud slinging as this is not why I'm posting this.How many of you folks have bought cheapy angle grinders, lets say under $40, and they've held up very well? Not really interested in the once in a blue moon users, but those that use them often and/or for hard grinding. My example: I've have one that I bought from Canadian Tire( auto/tool/hardware chain up here in, need I say, Canada....). It's a 4.5", cost me $19.99 can., came with a 3 year warranty( return and you get a new one). I've had it for 4yrs and use it for my ****ty grinding work. I.E. grinding off heavy rust and thick mill scale with a 4" stone cup and/or stone disk. Really leaning on it. It's not my favourite as far as it's body is too big for my hands and not comfy for one handed use.( Makita's are my fav for that, Bosch a close second) But it just take a $hit kickin' and keeps on tickin'!!! Any one else have one that is cheap and just goes and goes?Regards,Bert200amp Air Liquide MIG, Hypertherm Plasma, Harris torches, Optrel helmet, Makita angle grinders, Pre-China Delta chop saw and belt sander, Miller leathers, shop made jigs etc, North- welders backpack.
Reply:Thanks for the info 7A. I had a Craftsman too but it blew up( alum gear housing cracked open suddenly, wasn't being used have. Probably just a bad cast)I've currently got running 2 Bosch, 3 Makita, and the cheapy Master Craft( Can. Tires house brand). All run great( Can you tell I don't like changing disks?? ). Two of the Maki's are probably 8 years old. Never repaired or greased.200amp Air Liquide MIG, Hypertherm Plasma, Harris torches, Optrel helmet, Makita angle grinders, Pre-China Delta chop saw and belt sander, Miller leathers, shop made jigs etc, North- welders backpack.
Reply:I have 2 Black and Decker's that I got at Wally World for $24.99 ea. for doing the real crappy stuff and those are the grinders that I let others use. The first one crapped out in a matter of just a few hours, took it back for an exchange and now have had them both for a few years each. One of them is starting to make some noise in the head gears but it keeps on going. The only down side to these grinders is the lack of a paddle switch, I don't care for the on/off switch as I think it's a bit of a safety issue but, the upside to these grinders is that when they break they don't hurt your feelings to trash them or your pocket too much to replace them.I actually think I use them more than the 3 Dewalts and the Milwaukee that I also have.I am what I am, Deal with it!If necessity is the Mother of Invention, I must be the Father of Desperation!
Reply:I have a black & decker. It doesn't get heavy use, but it has given me more than the $40 or so that I paid!Also, there is a local used tool shop that has a handful of old makitas 4" grinders missing dhandles and wrenches for about $10-15 a piece. That's a good cheap grinder.
Reply:I hate to say it, but my favorite grinders happen to be the 40 dollar Ryobi grinders from Home Depot (ones with rotating trigger switch, and 3 position side handle).  Can't say the 3 position handles help me any, but that has been one of the better grinders I have used, and has held up surprisingly well (knock on wood).  I've got one that is starting to chatter a little bit in the head gears and bearings, but it still works fine for me, and gets used every day that I'm in the shop.Who is John Galt?
Reply:I also have a Home Depot Ryobi that has taken a real beating.  I bought a $20 Harbor Freight grinder that works well, however, after using it for an extended amount of time, it gets very hot.  The body of the grinder gets so hot that you can not hold it without wearing gloves.  The H.F. grinder works great, however I worry that it will overheat or burn up.  I believe the Ryobi is much more resilient when grinding for extended periods of time.*************************************Mike AccardiHenderson, [email protected] 250XLincoln Weldpack HDMiller Syncrowave 180 SD*************************************
Reply:A couple years ago I picked up a no name 4 1/2" grinder from norhtern tool for $25. Stripped gears within a couple hours use. That turned me off any cheapies (grinders anyway). I use a Dewalt for now. Makita's are alright too. I haven't found the "perfect" grinder yet.JasonXMT 350 MPA Dynasty 280DXSuitcase 8RC / OptimaSpoolmatic 30AThermco Ar / C02 mixerAssorted O/A gear
Reply:Originally Posted by bassboy1I hate to say it, but my favorite grinders happen to be the 40 dollar Ryobi grinders from Home Depot (ones with rotating trigger switch, and 3 position side handle).  Can't say the 3 position handles help me any, but that has been one of the better grinders I have used, and has held up surprisingly well (knock on wood).  I've got one that is starting to chatter a little bit in the head gears and bearings, but it still works fine for me, and gets used every day that I'm in the shop.
Reply:Over the last 30-some years I think that I have had angle grinders from just about everyone that makes them but I keep gravitating back to Bosch with DeWalt a close second recently. I don't use my grinders every day now but for a long time when i worked on race cars I more or less had an angle grinder attached to my hip I think.Anyway, my pick is the Bosch now because it runs so smooth, lots of power and it is very comfortable to use.I have reviews of a few angle grinders with photos and video  (Click Here) if that kind of info would help.Tom Hintz, publisherwww.newmetalworker.comLincoln Pro Mig 180Lincoln AC 255Determination
Reply:I have 3 of the Home Depot Ryobi  grinders.  One of them is 5 or 6 years old, no sign of failure yet.I'm not a welder, but I do sit next to one at the bar.
Reply:With Harbor freight tools you have to know which tools are worth buying and which ones are not. The blue electric tools are not worth the box they came in.Some orange tools are. The HF 4-1/2" grinder is one of them. I use mine virtually every day. I use mine to the point where I typically wear out both sets of armature brushes. These grinders are typically on sale for about $17 several times a year. After 100's if not 1000's of hours of usage I simply find little fault in them. About the only problem I have ever had with any of them is one grinder broke the locking pin for locking the wheel when using the spanner wrench. As I had already run 2 sets of armature brushed through it I cut the chord and tossed it. When you change the armature brushes be sure to blow out the dust and sand the armature with sand paper. You can fold it real narrow and pit a small wire down to hold pressure on the sand paper.They actually sell two slightly different models of the same thing. Both equally well but the armature and spanner are not interchangeable.I abuse these tools! Harbor Freight also sells a thin cut off grinder wheel. I buy these by the shopping cart load. They are a fraction of the price of department store name brand cut off wheels. I use these exclusively!!! They cut like there is no tomorrow and they are easy and accurate to grind with weather you are grinding down mower blades or grinding down a weld.The HF thin cuttoff wheels do disintegrate faster then name brand cut off wheels but....they also cut and grind better! I started using name brand wheels and soon found the jobs took longer even though the wheel which cost 3x as much lasted a bit longer. NOW since they grind down faster, safety gear is a must! Not JUST ear protection and safety goggles but you might start using a face shield. They do fly apart some times; and yes these grinders with thin wheel disk are wicked and un forgiving!!!! Just because my photos show the shield off doesn't make it a good idea! Always be conscious of which way it is pulling or grabbing. It is easy for these things to grab and take off. Once making a Jeepster dolly I was sitting down making adjustments with the grinder. It flew out f my hand, bounced between my legs and landed in my lap. My apron wrapped it up and stopped it right at my belly!!!   I'll take luck when I can get it but I try to avoid situations which create this type of risk.....Use it enough though, and they will bite you. I still have 10 fingers though. I count them every night! Just a few Harbor Freight grinder projects:http://www.rc-tech.net/disp/disp14.jpghttp://www.rc-tech.net/pantera1/zfmount/mo1.jpghttp://www.rc-tech.net/pantera1/zfmount/zfm2.jpghttp://www.rc-tech.net/pantera1/ladder/pad3.jpghttp://www.rc-tech.net/cars2/oldscam.jpghttp://www.rc-tech.net/pantera1/frame/frame4.jpghttp://www.rc-tech.net/pantera1/ladder/lad4.jpg
Reply:Safety protection:I also meant to mention dust mask. The majority of dust created is from the disintegrating grinding wheel. This stuff is bad in the lungs.
Reply:black & decker from wally world for me . i own 6 of the 4.5 in grinders, with one of them being over ten years old still hav it still use it everyday.BTW it helps if you realize the capabilities of a 4.5 in grinder.if you need a 9in grinder use a 9in grinder. i have one friend of mine that burns up dewalt makita,milwakee every week at least one a week,bcause he doesnt use a 9in when he should be.MM 251MM 135Lincoln Pro cut 55Bobcat 250Miller Thunderbolt ac/dcolder ac forneyJackson nexgen 3n13-Smith OP setups97 Dodge dieselMakita chopsawJet swivel head bandsawlincoln tig 300/30030a spoolgunpuma port. gas air comp.
Reply:Hey guys,Glad to see the fellows post their honest opinion/experience with some of the less-expensive units. For years at work, I used the DeWalt 4.5" grinders & they were pitiful. I had one I sent back 8 times because everytime you turned it on & touched the work, the vibration would trip the damn switch to off. I finally took the sledge to it. The German made Bosch was the best & it lasted 10yrs. Finally the gearbox went out & the boss told me he was going to HF to get cheapies & to use them till they blew up, & if they were still under warranty in a couple months, he would get them replaced. He said the new Bosch were made in China & he wasn't going to spend what they wanted when he could get (3) HF ones for the same price. I told him to get the orange paddle-switch units as they were the heavy-duty ones & I have one that has been superb for 5yrs now. I eventually bought (3) of them for myself for my shop & mobile unit. They, for some reason, quit making the orange paddle-switch one & finally last year brought back the p/s in a red unit. I have (2) of them & they work quite well & I use them brutally at times. The best protection to get good life from them is, as soon as you bring it home, take the gear cover off, clean out the yellow crap inside, & repack with blue lithium grease. That made all the difference in the world having them last longer. Anymore, I just treat them as another consumable.Denny Attached ImagesComplete Welding/Machine/Fab. ShopMobile UnitFinally retired*Moderator*"A man's word is his honor...without honor there is nothing.""Words are like bullets.... Once they leave your muzzle, you cannot get them back."
Reply:I have five HF grinders.  Two with cutting disks, one each with metal brush, grinding wheel and flap disk.  It's about an $80 investment for all of them.  As a hobbyist, that's worth the downside of one of them potentially failing mid-project and needing to be replaced.  (If I welded for a living, I'd have a few Metabos.)Jack OlsenMy garage website
Reply:we've got a bunch of the canadian tire 4 1/2" $20 grinders,  and a couple of thier 5" grinders......   we've been extremely happy with them....    one 5" has outlasted 2 rebuilds on a walter grinder,  that was 5 times the price,  and only used half as much..Bill BerryKeith Berry & Son Ltd.machine work, and weldingBear River Vollunteer FD
Reply:I started out buying the better brands and then the cheaper ones, and now I am going back to the better quality brands. Over the last 7 years I have lost count of the number of  times I have had to replace the cheaper ones. Some have lasted less then 15 minutes others have lasted 1 year or so, but when I thought about how many times I used those ones that lasted longer in that time, the total working hours weren't great.   So now it's back to paying 2-3 times more than I would a cheap tool but getting reliability and quality back. Some have proved to be downright dangerous. For example when I was off the ground  hanging on to a structure grinding away and the disc locking button lets go and the entire head shatters into pieces. Or when doing the same and the grinder just does want to turn off,  etc. I have gone through about 5 cheap grinders this year alone!!! For home use with occasional use they are fine , if you use them often then I wouldn't  use them again.Miller Auto Invision 456 + S-62 wire feederC6240B1 Gap bed lathe16 ft3 air compressor16 speed pedestal drillHafco BS-912 Bandsaw
Reply:Originally Posted by yorkiepapHey guys,Glad to see the fellows post their honest opinion/experience with some of the less-expensive units. For years at work, I used the DeWalt 4.5" grinders & they were pitiful. I had one I sent back 8 times because everytime you turned it on & touched the work, the vibration would trip the damn switch to off. I finally took the sledge to it. The German made Bosch was the best & it lasted 10yrs. Finally the gearbox went out & the boss told me he was going to HF to get cheapies & to use them till they blew up, & if they were still under warranty in a couple months, he would get them replaced. He said the new Bosch were made in China & he wasn't going to spend what they wanted when he could get (3) HF ones for the same price. I told him to get the orange paddle-switch units as they were the heavy-duty ones & I have one that has been superb for 5yrs now. I eventually bought (3) of them for myself for my shop & mobile unit. They, for some reason, quit making the orange paddle-switch one & finally last year brought back the p/s in a red unit. I have (2) of them & they work quite well & I use them brutally at times. The best protection to get good life from them is, as soon as you bring it home, take the gear cover off, clean out the yellow crap inside, & repack with blue lithium grease. That made all the difference in the world having them last longer. Anymore, I just treat them as another consumable.Denny
Reply:Originally Posted by boilermaker1Do 4 1/2 inch grinders in the US come with wheel guards I would never use a grinder without a wheel guard and if I did at work I would get my Butt kicked!
Reply:Originally Posted by theonlybullwe've got a bunch of the canadian tire 4 1/2" $20 grinders,  and a couple of thier 5" grinders......   we've been extremely happy with them....    one 5" has outlasted 2 rebuilds on a walter grinder,  that was 5 times the price,  and only used half as much..
Reply:I have 3 different grinders. The first one I bought was an orange HF for $17. It's been pretty good for a few years now (though it wasn't used very much for a portion of that time). The screws that hold the brushes and the tail housing onto the grinder keep coming loose (and may be somewhat stripped). I've still been using it, but I have to tighten the screws almost everytime I pick it up.I bought a Ryobi ($30-35 at Home Depot) and have used it fairly heavily on my recent roll cage project and some other uses. It's holding up perfectly so far and it's been lightly abused.I found a sale at Tractor Supply on a Kawasaki brand (someone licensed the name) grinder for $19.99. The shaft doesn't run true and the gearbox sounds like it's full of rocks. I'm going to swap a flap disk onto it due to the shaft wobble. I'll use it until it's worthless (that's not much of a trip from here) and toss it. Based on my experience, I'd pass on that one. However, I bought a Kawasaki electric sheet metal sheer (based on a power drill) and it is rated for 14 gauge steel, works great and was $69 (Milwaukee was 16 or 18 ga rated and $189). So I can't say all of their stuff is junk, but buy at your own risk.KevinHobart Handler 210Tweco Fabricator 181iLincoln Squarewave Tig 175
Reply:I have several HF ones (orange) and they do get pretty warm but never give up.  I also have a Home Depot Ryobi and it works good but is somewhat larger and difficult to get into tight spaces.  I would buy the HF again if I needed a new one.Please dont mistake my enthusiasm for talent!
Reply:The biggest problem with the cheapy grinders is that they have bushings instead of bearings.  I had one of the bushings go out.  I replaced the bushing with a bearing and it lasted for several years of hard use.  Don't remember the bearing number though.
Reply:I also use a 9" when warranted...use a 4.5 inch Porter Cable that has worked ok for the last year...the unreal workhorse has been an old B & D 4" industrial (80's?) with who knows how many hundred hours on it...just keeps on going.  probably the most hours/dollars return on investment I've ever had.
Reply:I have had a Clarke 4.5 grinder for over ten years. It was bought at tractor supply. I have USED the crap out of it. I also have two "blue"  HF specials.......and really nothing special about them. They still work, but are very roughI have a paddle switch HF that is strong. An orange HF that runs good but not as strong. A blue variable speed Clark that is strong but runs like crap at less than full speed. I bought a 2-pack of nice looking Kawasaki grinders and gave them as Christmas gifts 2 years ago. I was embarrased to learn they were junk - didn't last a day.Lincoln SA200, HH135, Lencospot, HF80 Inverter, Rockwell 11x35 lathe, HF drill mill, Kama 554 tractor w/ FEL & BH, Belarus 250AS, lot's of Chinese tools
Reply:I just bought my second 95578 Harbor Freight "Drill Master" black handled 4-1/2" Angle Grinder for only $10 with coupon.  Liked the first one so much...  (first is still working fine, BTW.)http://www.harborfreight.com/4-1-2-h...der-95578.htmlIn comparing with the other 4" & 4.5" angle grinder models offered by Harbor Freight, I like how the 95578 is not as long; more compact.  Also it has good looks, IMO.  Yet it weighs about the same and has about the same motor amp rating (4.3) as the other supposedly more "heavy duty" models (rated at 4.5 amps.)  The switch seems a little chinsier than alternative switches, but I like how its located centrally (on top).  It is spring loaded, but has a lock by pushing down, that can be operated with one thumb.  I found some of them have smoother operating switches than others (so, may be worth opening a few boxes and selecting the best.)And what I like about the 95578 is that it has a metal gearbox bottom cover.  (The other supposedly "Heavy Duty" models that had this part made out of PLASTIC!)  The spindle lock of the 95578 seems noticeably chinsier, however.  The spidle lock button kind of racks around and moves side to side.  Not as confidence inspiring as the other models.The 95578 doesn't include any type of wheel inside the box, whereas most of the other models include one grinding wheel.If you are worried about a cheap grinder breaking in the middle of a job, just pick up a second one to have as a backup.  I plan on have both of mine set up at the same time and switching between them, one with a flap disc and another with a cutoff wheel.  Should cut down on wheel change time compared to having a single, more expensive angle grinder.    IMO, at the $10, its hard to beat the 95578.  A 2 year extended warranty "no questions asked, will be exchange for new" was available for an additional $4.
Reply:Wow.....I think you win for the categories of : "Cheapest price cheapy" and " Cheapest sounding name", also "poorest name choice" honor as aswell!!!!Funny though, as cheapest of the cheap it is, the designer was thoughtful enough to put the two peaks at the top of the gear housing so you can put it upside down, on the bench whilst it's still spinning.  Originally Posted by jakeruI just bought my second 95578 Harbor Freight "Drill Master" black handled 4-1/2" Angle Grinder for only $10 with coupon.  Liked the first one so much...  (first is still working fine, BTW.)http://www.harborfreight.com/4-1-2-h...der-95578.htmlIn comparing with the other 4" & 4.5" angle grinder models offered by Harbor Freight, I like how the 95578 is not as long; more compact.  Also it has good looks, IMO.  Yet it weighs about the same and has about the same motor amp rating (4.3) as the other supposedly more "heavy duty" models (rated at 4.5 amps.)  The switch seems a little chinsier than alternative switches, but I like how its located centrally (on top).  It is spring loaded, but has a lock by pushing down, that can be operated with one thumb.  I found some of them have smoother operating switches than others (so, may be worth opening a few boxes and selecting the best.)And what I like about the 95578 is that it has a metal gearbox bottom cover.  (The other supposedly "Heavy Duty" models that had this part made out of PLASTIC!)  The spindle lock of the 95578 seems noticeably chinsier, however.  The spidle lock button kind of racks around and moves side to side.  Not as confidence inspiring as the other models.The 95578 doesn't include any type of wheel inside the box, whereas most of the other models include one grinding wheel.If you are worried about a cheap grinder breaking in the middle of a job, just pick up a second one to have as a backup.  I plan on have both of mine set up at the same time and switching between them, one with a flap disc and another with a cutoff wheel.  Should cut down on wheel change time compared to having a single, more expensive angle grinder.    IMO, at the $10, its hard to beat the 95578.  A 2 year extended warranty "no questions asked, will be exchange for new" was available for an additional $4.
Reply:I think that black 'Drillmaster' model might be the replacement for the old (blue) regular duty grinder.  It has less power than the Heavy Duty (orange) model, and is cheaper.  Both have aluminum ahead of the handle.  The paddle-switch one (red) is even more powerful than the Heavy Duty model.  All that said, I've got blue and orange models and all of them have held up fine.  I don't notice any significant difference in normal use.And the black body looks good.Last edited by Jack Olsen; 10-20-2010 at 09:17 PM.Jack OlsenMy garage website
Reply:I just bought a Harbor Freight orange grinder and this thread makes my $20 grinder feel like its going to give me $70 worth of life, also their cheapie cut-off wheels do work amazingly well for as cheap as they are.
Reply:Originally Posted by bert the welderWow.....I think you win for the categories of : "Cheapest price cheapy" and " Cheapest sounding name", also "poorest name choice" honor as aswell!!!!Funny though, as cheapest of the cheap it is, the designer was thoughtful enough to put the two peaks at the top of the gear housing so you can put it upside down, on the bench whilst it's still spinning.
Reply:I opened up the two Harbor Freight 95578's I've got.  I generally liked what I saw inside!  First off, I was surprised each had a unique serial number, and a manufacturing date.  That might allow some quality control.The design had ball bearings on both ends of the motor&pinion gear, and a ball bearing plus a roller bearing on either ends of the ring gear.  No bushings to be seen!The electric windings were nice n' laquered (looked pretty dust resistant.)  Armature was balanced.  No metal shavings left behind, improperly torqued fasteners or other missing parts, or other evidence of sloppy assembly to be found.My biggest criticism is that the circlips holding on the gears, and the half moon key between shaft and gears was a little sloppy fit.  In reality, I don't know if it matters much for the performance of the tool.There was possibly an OK amount of grease (see pictures), but I added much more.  I did also deburr the cooling air intake passages in the handle. Attached Images
Reply:Originally Posted by jakeru  Gow589 - thanks for your detailed review and info about the harbor freight angle grinders and accessories earlier in this thread.  Based on your review, I picked up a five pack of the thin (3/64" thick) 4.5" harbor freight cutoff wheels also.  On their first use today, those were allright!
Reply:gow589 - you got it.  By the way, if you use cutoff wheels for grinding, only the edge of the wheel should be allowed to make contact, not the face... correct?Also, I attached some more pictures of the harbor freight grinder disassembly.  First two pics are of the gearcases of the two grinders I opened up, as they appeared right being opened.  Second one seemed a little dry / shy on grease.  Also, one, with the earlier manufacturing date, was missing a circlip retaining the pinion drive gear from falling down when the gearcase was disassembled.  I don't know if that is a manufacturing defect, or a design change between the two grinders.  (they had different build dates.)  Third pic showes a bit sloppily cut half moon keyway (excessive chamfering visible on the edge of the slot, sloppy overall fit), and fourth pic shows my deburring job of the air intake holes (completed on left side, still original on right.) Attached ImagesLast edited by jakeru; 10-21-2010 at 12:58 PM.
Reply:I actually have several ways I use it. I do use the face a little depending on the situation, but more so just at a shallow angle. You can go back and forth and work layers fairly well. Also, after some passes, I turn the grinder over because one side is kind of scraped off a little and you can work the other side of the wheel. Be sure to wear glasses and other gear. These things really shed but I think their tendency to shed also contributes to their effectiveness. In some situations you can steady your grinder in your hand at a near right angle and pivot it back and forth with real good control over the progress.
Reply:Here is an example where I used the thin wheels on fender flairs. The flairs on this car were overlapped. Before I stripped the car, filler was used to smooth the edges and the filler was cracking in the flairs. I cut the flairs and welded them flush. The thin HF wheel was great as it gave great control over the depth. Since the wheel grinds well, it does not heat up as much. A grinding wheel that does not grind as well heats up more. Primer with no filler:
Reply:Been through my fair share.  The cheap ones smoke up the shop eventually, the good ones keep going.  My longest running was a Skil, about 20 years before death and landfill, that's a whole lot of grinding for a 4.5 that cost about 30 bucks back then.  The spindle bearings gave out.  I tossed it.I have a couple Metabo's that I bought used at a garage/auction sale.  I'd never pay retail or even close.  Metabo's are overrated.  My favorite is the Porter-Cable that I bought for 35 bucks at Lowes.  Plenty of guts, runs cool.  I tend to use them real hard.  I also have 2 big Dewalt angle grinders but I find the little ones easier to handle.
Reply:gow589 - Those are some seriously impressive, nice looking fender flares.  I wish I had those on my race car; then I could lower it more.  Maybe some day.  I'm sure it took a lot of work.  Thanks for the tips on how to grind using the cutoff wheels.  Looking forward to giving it a try!  So much quicker method of cutting steel than my die grinder or hacksaw.Any solutions to cutting aluminum with an angle grinder?
Reply:I have cut aluminum with these wheels which work; but is still a bit like cutting hard bubble gum. I prefer a band saw. The trick with a band saw is a fresh blade. I do add a little "aluminum tap magic" but I am not sure it helps. Ideally a bandsaw with liquid would be best but I am afraid I am tied to a generic model. With a new blade, like butter. Old blade like pulling teeth. I forget how bad it is till I change it:http://www.rc-tech.net/pantera1/airdam/ad.htm
Reply:Originally Posted by Brad BlazerI have a paddle switch HF that is strong. An orange HF that runs good but not as strong. A blue variable speed Clark that is strong but runs like crap at less than full speed. I bought a 2-pack of nice looking Kawasaki grinders and gave them as Christmas gifts 2 years ago. I was embarrased to learn they were junk - didn't last a day.
Reply:Just got a coupon in my email for HF grinder the black and red one for $18 which they say is regularly $30. After reading these reviews, I'm gunna pick one up.On Halloween they have 10 of those 4 1/2" cutting wheels for $6.Last edited by zhillz; 10-22-2010 at 03:45 PM.
Reply:I thought I was the only welder with 6 or 7 grinders Started out 30 years ago with my fathers 7 inch aluminum bodied B and D . I takes off metal like no tomorrow and after a couple days of use you will have arms like a Bodybuilder. It never lacked power. Used it with grinding wheel and a large wire cup. All I have ever done to it is repack the gears with grease, blow the dust out of it and replace brushes when needed. It did just fail me last week. Plugged it in to do a job and it took off across the workbench onto the floor pulling the plug from the socket  The trigger is pooched. not sure if I can find a replacement  The next best died this week. My 4 inch Bosch  just barfed the gear case. bought it in 1990. Just replaced the brushes for the 1st time a year ago.  have 2 Princess Auto ( canadian version of Harbor freight ) 5 inch variable speed grinders that get beat grinding and running 3 inch wire cups for hours on end. Still running strong. 1  -- 4.5 inch skil has been very good and my favorite as I can 1 hand it when needed. 3 canadian tire 4.5 inch grinders . they are a little clunky to handle but work well . They sell for $20 on sale and the 3 year warrranty is great. Have had 1 crap out after a couple days use- v ing out some 1/2 inch plate. Brought it to the store and they handed me a new one.
Reply:My Harbor Freight 95578 did a pretty nasty job well... cutting some old flashing out of the grout lines of a chimney, and cutting in a new reglet (angle cut, through brick and grout) in the chimney for some new flashing.  My building materials supplier said the dust from this job has been known to take out even the best brand of angle grinders on just one job.  I just held the HF 95578 so the air intake at the back of the handle wasn't sucking in too much dust, and let the "turbo style" diamond wheel remove material at its own pace, which cut pretty smoothly, like butter.  The grinder got the job done and ready to do it again 10 times!Also, we added a third 95578 ($10 coupon price) to the family, to replace my brother's 10 year old craftsman professional, made in usa.  The craftsman professional made in USA was a little but heavier duty, with a 2" diameter ring gear, vs. the harbor freight 95578's 1.8" diameter ring gear.  Cleaned out the grease of the harbor freight grinder and added fresh, Mobile 1 synthetic red grease, which is less viscous so should "flow" and work better better inside there when the gears get heated up. Attached Images