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What's the difference between the HF air angle grinder

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vanapplebomb

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You mean the angle die grinders?

If so;

-Heat treat of the bevel gears
-Backlash of bevel gears, aka, better tolerances on the depth of the pinion gear and contact area.
-Better Bearings
-Quality of motor parts, such as vanes, porting, deburring, etc resulting in better power and longer life.

Just to name a few.
 
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Don1357

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You mean the angle die grinders?

If so;

-Heat treat of the bevel gears
-Backlash of bevel gears, aka, better tolerances on the depth of the pinion gear and contact area.
-Better Bearings
-Quality of motor parts, such as vanes, porting, deburring, etc resulting in better power and longer life.

Just to name a few.

From a hone garage dweller perspective how much does that come into play?

I mean if you were on a business setting a single downtime would eat whatever you though you saved from buying cheap. I would probably put in a year as much tool time as those guys put in a week.
 

American Locomotive

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I am genuinely not sure what point you're trying to make here?

If you don't think a name-brand die grinder is worth it for you, buy the cheap one and see if it does what you want it to do. If it doesn't, replace it with something better. If it does, great!
 
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Don1357

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I am genuinely not sure what point you're trying to make here?

If you don't think a name-brand die grinder is worth it for you, buy the cheap one and see if it does what you want it to do. If it doesn't, replace it with something better. If it does, great!

Or I could learn from the experience of others by posting on a tool forum.

There are tools where it absolutely makes no sense to buy cheap, like screwdrivers and generic tools shaped like adjustable wrenches, only disappointment comes from those. There are tools where the cheaper alternative works every bit as good as the much more expensive ones, some hammers and my 2" clamps come to mind, I got HF and Pony of the latter, I reach for either when I need to use them). And there are tools that lie in the middle, and how you use them has a huge say in the matter.
 

vanapplebomb

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I use die grinders daily, and of many different makes, just for reference.

I have found the cheap $15-25 die grinders start having problems around year one, but sometimes can last a surprisingly long time. The biggest problem with the cheap ones are the gears. Poor mesh results in the gears wearing out and breaking. Surprisingly, as long as you keep feeding them air tool oil, the motors are not generally an issue. Air motors are amazingly durable. Expect about 1/4hp from these cheap grinders. Not particularly powerful, but still good for breaking edges, and light sanding, etc.

$30 die grinders have not failed me for 2-3 years. These typically are reasonably decent 1/4hp compact die grinders.

$50 die grinders I have used daily for 5 years. Now your talking 1/3hp, and better quality. You can reef on them a bit more when grinding, and really start chewing though material with burrs. Better gear mesh, and generally quieter. Similar in capability to the Milwaukee M12 die grinder, but much more compact, and without constantly eating batteries or getting hot.

When you start pushing $80, you can get some monsters. This starts getting into 3/4hp - 1hp range. Good to great build quality, and will really hog out material fast.

Then there are the $150+ which are often are pretty industrial duty units that will pretty much last a lifetime, are very smooth, and will take some serious abuse. Top notch bearings and motors. You can even get high speed turbine motors which need no lubrication, and can spin 100,000 rpm on a 1/4” chuck!

It would seem the trend is roughly 1 year of daily use per $10 spent on air die grinders.

For home use, the cheap ones may be fine, but I would still spend about $50 and have a nice unit that would last a long time with grunt when you need it. Lubricate it with air tool oil every time you use it, and the motor should be problem free for years.
 
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livinloud11

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The HF air grinders **** IMO, I legit have trouble cutting with them using a 60 gal air compressor at home and I always revert to my electric corded grinder because it is that bad. I am also talking about the very cheap air grinder that's like $10-$15.
 

sberry

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Or I could learn from the experience of others by posting on a tool forum.

There are tools where it absolutely makes no sense to buy cheap, like screwdrivers and generic tools shaped like adjustable wrenches, only disappointment comes from those. There are tools where the cheaper alternative works every bit as good as the much more expensive ones, some hammers and my 2" clamps come to mind, I got HF and Pony of the latter, I reach for either when I need to use them). And there are tools that lie in the middle, and how you use them has a huge say in the matter.

Don,,, you will get your moneys worth out of a cheap tool. As the apple said, the 30$ one is a different tool than the 10 sale or the 20$ one. The 30$ one is rebadged all over the world under various stickers they slap on it with various price levels depending on where it was sold.
 

sberry

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But,,, if you want brutal service these fill the ticket and in the same class as many more expensive industrial types. Don, these are a class heavier than you are talking about, smaller would be a bit cheaper but these been used like rented mules wayyyyyyyyy beyond what a homebody could ever put on them. How many years is one figure but service hours would be another and these run as long/longer than its parent design. That right angle is nice 4 inch, same for the wire wheel, got the power and never so much as had to tighten a single screw on one of them, decades of service now. Worked them regular for 10 years. I have used them against IR and CP, like them as good or better and they outlast them.
I dont think Don is a 20 something, a 50 yr old guy couldnt wear it out in the rest of his life. Wouldnt want to. But those are no fukkin around rip *** tools.
There is some fascination with smaller and tighter and 3/8 parts in 1/4 bodies but to tell the truth have learned to manage most of the same tasks with larger more powerful tools. Makes up in closeness by having a blade that reaches farther. My Bud has a 3 ich cut off as they oft called here but I rarely use it, I use 4 inch right angle. He has some grinder experience and I have hundreds of hours with dozens of types and this is what it boils down to if its humanly impossible to do it with a 4 1/2 electric.
 

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vanapplebomb

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The HF air grinders **** IMO, I legit have trouble cutting with them using a 60 gal air compressor at home and I always revert to my electric corded grinder because it is that bad. I am also talking about the very cheap air grinder that's like $10-$15.

Wrong tool for the job. The larger ones can be used for cutting sheet metal with a 3” cutoff disk, but that isn’t what they are for. Also, it is dangerous to use an angle die grinder with a disk...just ask my knuckles. When a disk comes apart, your knuckles are the first thing they will embed in. Sometimes you absolutely must use an angle die grinder when it is the only option that fits, but other than that, avoid. 3” cut off disks are much better for quick trimming on straight die grinders.

For cutting, a 4-1/2 angle grinder is the correct choice.
 

ZRX61

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Years ago I bought a bunch of their $7.99 die grinders. Each one has a different doodad on the business end.
Plan was to just throw them away if they broke. Can't recall when I bought them, but it was at least 12 years ago. All still working just fine.
 

2ndGearRubber

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For a home user? Probably not a ton. We're talking about the pneumatic 90* ones for like $15?

Typically guys can use them for a year in a shop. A loose nut keeping the bevel gears in contact is a death sentence on most. They're noisy and low on power, relative to higher dollar models, big surprise there.


Like many things: DIY use really changes what level of sturdiness you need. It's $15, who cares? Use it once a month, and it could last a decade or more.
 

Mr_B

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when you see some of the deal prices on ones from Napa or AP it no point buying total low end .
Besides durability they generally suffer poor power and poor air cfm efficiency .
 
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vanapplebomb

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Don, what do you have for a compressor? Die grinders, though small, are air hungry units. Even cheap 1/4 - 1/3 hp ones can draw 8-16 CFM at full song. The advertising is all over the map for them, and the number stated on the packaging is always at a duty cycle...usually a 25% or 50%. So a “4CFM” die grinder, in real numbers, is more like 8-16 CFM actual flow rate. For continuous use you are looking at a 230 Volt compressor.
 
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Don1357

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Lots of great info guys, I really want to thank everybody for taking their time on educating me.

Don, what do you have for a compressor? Die grinders, though small, are air hungry units. Even cheap 1/4 - 1/3 hp ones can draw 8-16 CFM at full song. The advertising is all over the map for them, and the number stated on the packaging is always at a duty cycle...usually a 25% or 50%. So a “4CFM” die grinder, in real numbers, is more like 8-16 CFM actual flow rate. For continuous use you are looking at a 230 Volt compressor.

I have a 60-gallon 13.5CFM@90. Heck 5.5 more CFM @ 90 PSI if I put my portable compressor inline. It doesn't need to be pretty, it just needs to work :D

For the 13.5 CFM, what would be decent around $50? While we are asking, what's good on a 4 1/2" angle grinder? That I abuse like you have no idea so I would want to get something decent, don't care to even look at the bottom end, but I don't have the air to really run a really powerful one.
 

Mr_B

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Have a look in current Napa real deal catalogue, sometimes have the carlyle alloy body BOGO or almost half price .
AP onyx another good one at fairly sensible price if shop about .
Sourcing kuani or m7 online can get some lower priced but nice air tools
 

sberry

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As for 4 1/2 this is all over the place and as many opinions as there are about oil changes. But,,,, I been at this a while and new cheaper tools are now about as good as older ones were with the benefit of being cheaper. So much is the same with a different brand on it at different price points.
I have used some Metabo, not many of the new models but was in a shop a while back, owner had a bucket of broke he was trying to get fixed. The 9.95 HF are not good but we got guys use them but North of that they start to improve. I am done with "better" ones, yellow, black, red and settle on the B&D I buy at Wal-Mart. Lots of power, runs smooth enough, never had to repair a cord on one and am on my 3rd one in a welding shop, we put one on the bench where it gets it daily, I even fixed a switch in one and it ran another couple years.
There are others now in this class but I bought 100$ grinders 30 yrs ago and now use a 30$ one I like as well or better. I actually like a paddle a bit better but I get used to it and these hold up better than the d402. Never burned up a brush in one, don't got to mind them and keep a new one in a box just in case. I use 1 on bench just to see how long they last.
While its difficult to determine how hard you can use it I really doubt a part timer can use it like a professional fabricator, both in brutal use, duty cycle and continuous use. This is another case of not much to lose if it gives it up after a while, by then it has well earned it's keep.
I would have more but I only use them hard wheel as I have the rest of the stuff on air but wouldn't blink at getting a box of them and putting different wheels on.
I had another forum type shop owner pm me,, says don't tell but I use them too.
 

sberry

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All this doesnt need to be as agonizing as it used to be. Tool quality has surged and priced dropped. The very cheapest models in a line are not good, there iz a limit to how low it can go. The next step up is now often the generic tool gets a mid brand on it at 2 or 3x the price.
Use a while if not happy spend 100 or more instead of 30. I used to spend 100 and back when I did the 30 or 50 was not what it is now. 30 yrs ago a 50$ battery drill was a toy, today it's a working tool. I pic it ahead of my professional models, the 30$ grinder has become my go to.
Be different if it didn't work, didn't last, didn't have the power but a guy soon forgets the cost if he runs it a while.
 

ex-x-fire

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Some of those cheap air die grinder only have power at 100% but the speed is very high and so is the vibrations. They feel like they're gonna blow up.
 

joshmodelskidoo

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Dropped my hf one and the air fitting snapped off but it was the tool that broke not the fitting so i went and got another one. Eventually that one got sloppy after a few years so i took both and made a good one and used it for a bit then gave it to a friend. It will probably last him and his kids there life time. I went with the $30 porter cable from tsc. Its been nice so far and has a rubber over mold handle and for those little air suckers thats a must for me with the cold tool and vibration. I acquired an ir with no over mold and after using that the hf just wouldn’t do me. Guess what im saying is it depends on how much you use it. If its not much go with a cheap one and if you use it more than you think upgrade when it dies. I have a $6 hf 3in cut off wheel and i have had it for years. When I first got it i had to give it a bump to make it run but now it’s fine and most likely I will have that one for ever. I got a coleman power mate straight die grinder from menards pretty cheap and I really like that
 

vanapplebomb

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Dropped my hf one and the air fitting snapped off but it was the tool that broke not the fitting so i went and got another one.

Yes, the inexpensive ones usual have an adapter threaded into the back. 1/4”NPT female on one end for the air fitting, and something like a 10mm male straight thread on the other end that goes into the body of the tool. With most those pieces being aluminum it is very easy to damage. Dropping for example, or tightening an air fitting without a wrench on the tool end.

My fix for this is simple, take the tool apart and remove the air motor So chip don’t get in it. use a reverse spiral ez out (or similar) to remove what is left of the 10mm male thread in the tool that broke off. Then, tap the hole out to an 1/8” NPT, being careful not to go too deep and get into the valve body. Then, take a blow off gun, depress the throttle valve, and blow out the chips FROM THE INSIDE! Aka, blowing in through the motor housing side, and out through the air fitting side. Then just thread in a 1/8” male ****** and adapt to a 1/4” NPT for the air fittings. The 1/8” brass ****** is much stronger than the 10mm aluminum male end. Then drop the motor back in and screw the retainer on. Done. Much stronger than before. It takes about 3 minutes to do. On cheap tools, I do this automatically right out of the box on new tools.
 
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vanapplebomb

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Lots of great info guys, I really want to thank everybody for taking their time on educating me.



I have a 60-gallon 13.5CFM@90. Heck 5.5 more CFM @ 90 PSI if I put my portable compressor inline. It doesn't need to be pretty, it just needs to work :D

For the 13.5 CFM, what would be decent around $50? While we are asking, what's good on a 4 1/2" angle grinder? That I abuse like you have no idea so I would want to get something decent, don't care to even look at the bottom end, but I don't have the air to really run a really powerful one.

With that compressor, you should be good for any 1/3hp range die grinder. Honestly, take your pick at $50. They will all be decent units at that price. Pick one up from a place that backs a warranty if your that kind of person. Since this thread started out with Harbor Freight, the Chief ones from harbor freight are actually pretty good, and they will take it back no questions asked.

As for 4-1/2 air angle grinders, I love them. Much more compact and way more durable than electric grinders. I had trouble getting any electric one to last much more than a year. If an air one crapped out in less that 5 years of abuse I would call that a total failure. I would want to see 10 years out of any air angle grinder. That said, that’s not something I would recommend with your compressor. I had an IR, and now a 1.3hp M7 which is awesome, but my 80 falling two stage compressor just keeps up with it. You may be able to get away intermittently with out it being too frustrating with your compressor with a .9hp ish grinder. Again, harbor freight has a decent one for $90 or so. I believe it is made by Florida Pneumatic, but don’t quote me on that.
 

MatcoDave

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I'm a heavy duty mechanic that uses die grinders at least several times per week. My first HF angle grinder lasted about 8 years. Initially, the reverse threaded retainer that holds the shaft in the body would come loose often. I removed it, greased the gears, wrapped the retainer in Teflon tape and reinstalled. Never had a problem until the cast aluminum actually failed on the angled head - probably from being dropped one too many times. I replaced it with another and Tefloned the head right out of the box. It's been going strong for the the last 2 years. If and when this one fails I will purchase another one. $20 or less for a tool that served me well for 8 years seems like a pretty good deal to me. Keep the motors oiled and heads greased and I'm sure it will be just fine.
 

NUTTSGT

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I bought a HF 90° die grinder as I didn't have one. I wanted to try one out to see if I liked it. After it died in about 1-2 years, I bought an IR set. They have been going strong and no issue.
 

Gummi Bear

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I bought a HF to try out after using my buddy’s.

It did the job, but bogged down pretty easily. I used it for a couple of years (I’m a weekend hobbyist, so it doesn’t see daily use)

I upgraded to an Air Cat. Holy moly, talk about a difference. The 6280 is .75 hp. Comfortable to use, lots more power. It doesn’t bog down nearly as much.



I went to the woods because I wished to live deliberately...

Henry David Thoreau
 

marineman

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I believe the dewalt grinders you can get on Amazon are the same as Mac. I have the mac version and would recommend it as a good middle of the road. The problem i had with the harbor freight ones was the vibration would make my hand go numb almost instantly. I have about 10 grinders in my box all for various uses and pretty much all the cheap ones are the same.

Sent from my SM-G970U using The Garage Journal mobile app
 

vanapplebomb

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I bought a HF to try out after using my buddy’s.

It did the job, but bogged down pretty easily. I used it for a couple of years (I’m a weekend hobbyist, so it doesn’t see daily use)

I upgraded to an Air Cat. Holy moly, talk about a difference. The 6280 is .75 hp. Comfortable to use, lots more power. It doesn’t bog down nearly as much.

You are right. The cheap less than $20 ones are not well balanced at all, and the lowest power of the lot. Noisy too. Good for deburring and light sanding...that’s about it. The Chief line from HF is considerably better.

Those die grinders larger than 1/2 hp are monsters. Like that 3/4 hp air at you have. Florida Pneumatic really stepped up their game with their Aircat brand. Good stuff. Those are a screaming deal too, for what they are. It’s hard to beat the value for money on those big die grinders.
 
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