Looking for a quality USA made angle die grinder for general rust removal, gasket prep, etc. Originally was going to get the IR 5102MAX die grinder. Started doing search here and found maybe a used industrial die grinder like Dotco, Dynabrade, Souix, Atlas Copco, industrial IR, etc from eBay might be a better choice (depending on condition and auction price). I have a few questions. Don't know what RPM to get, seems like 12,000 and 20,000 are common choices. Will a 0.3 to 0.4 HP model be adequate for the general stuff I need to do? I guess another factor in all of this is my compressor is a Kobalt 45gal rated 10.1 SCFM @ 90psi (not even sure if I have enough compressor to run a die grinder, some specs I've seen show 11-15 SCFM free-spin and 20+ SCFM @ load). Anyway a Dotco 12LF series and Ingersoll Rand G1 series have caught my attention on ebay. Both look about same condition and prices are close. Any prefernce between the two?
advice on die grinders
- Thread starter enrare
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Letsgobowhunting
Well-known member
I am all about USA but the last thing I would do is purchase an air tool from an auction. I would buy a Central Pneumatics before I buy used. That's just me though.
IMO a die grinder is a die grinder. ive had a bunch of different die grinders. matco, craftsman, hf, and a couple midgrade stuff i bought at industrial stores. the matco 5 hp that i have are better than the hf but really the only noticable difference is when cutting the hf bogs down when pushing too hard and same thing when using burrs. but for using sanding/roloc pads and flap disk they all do about the same. the matco is also alot larger than the hf and other midgrade brands i have.
for cutting/heavy grinding purposes you more hp will let you push a little harder without the grinder bogging down which lets you cut quicker. so if that benefit is worth the extra money go for it.
for sanding/cleaning/light grinding more rpm are beneficial.
all in all personally id rather have 4-5 cheap die grinders all with the different attachments and such so i dont have to constantly switch the bit.
if your set on a name brand id probably go IR. not sure about the model id pick but id probably go with higher HP if your gonna spend the money. i wouldnt buy online either. die grinders are one of the air tools that have a higher tendency to go bad than other air tools. the high rpms/lack of lubrication(unless your **** about oiling your die grinder) tend to ruin the bearings
for cutting/heavy grinding purposes you more hp will let you push a little harder without the grinder bogging down which lets you cut quicker. so if that benefit is worth the extra money go for it.
for sanding/cleaning/light grinding more rpm are beneficial.
all in all personally id rather have 4-5 cheap die grinders all with the different attachments and such so i dont have to constantly switch the bit.
if your set on a name brand id probably go IR. not sure about the model id pick but id probably go with higher HP if your gonna spend the money. i wouldnt buy online either. die grinders are one of the air tools that have a higher tendency to go bad than other air tools. the high rpms/lack of lubrication(unless your **** about oiling your die grinder) tend to ruin the bearings
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A lot of the new IR die grinders are no longer made in the US. I like industrial brands like Dotco, Cleco, ARO, etc. They have repair parts (except ARO). Ask the ebay seller to verify that it is still working. I bought 7 used die grinders (Dotco, Sioux, IR, Snap On) at the flea market and two were bad (Snap On and Sioux). Since die grinder spin at very high rpm, they tend to wear out alot faster than other air tools.
Mohawk Dave
Well-known member
don't buy cheap ****. Especially on die grinder. BIG difference on a good one. Like oldtools list of good ones...
There's rebuild kits on the eBay for old Dotco and IR ones...but the used ones I've picked up didn't even need a rebuild, just a good cleaning. I ran a bunch of Marvel Mystery Oil and Tri Flow through my estate sale finds, then after that just the normal lube of MMO each use.
There's rebuild kits on the eBay for old Dotco and IR ones...but the used ones I've picked up didn't even need a rebuild, just a good cleaning. I ran a bunch of Marvel Mystery Oil and Tri Flow through my estate sale finds, then after that just the normal lube of MMO each use.
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JonnyMac
Well-known member
I just bought IR angled die grinder from amazon, less than $60. About the cheapest place I could find and i cant fault it...
Dave455
Well-known member
I use my air tools a lot, especially my die grinder, mainly because of their durability. Decent air tools are all metal construction and can take serious use in a shop where plastic bodied power tools will not! That's why I buy them!
For many years the IR die grinder was pretty much industry standard in the U.K. All but the cheapest in the range were US made, and decent quality too!
Sadly, over the last couple of years that's changed! Aside from being made god knows where, IR havn't attempted to even make the same tool any more! The current offerings all seem to have loads of plastic - and I refer you back to paragraph one in that regard!
So, what to do? If you go down the Taiwanese route, don't believe all the shite the manufacturers, correction importers, come out with such as "it's made in 'our' factory in Taiwan, to 'our' standards"! It will be made in the same factory as all the others, to the same standard! The only thing that will vary is the price, so buy the cheapest!
An example, I recently looked at air files! Snap On have got their Blue Point on a special offer for, I think, about £160 at present! I can get the same tool (exactly the same tool, but painted red not blue, for £40 elsewhere!
If you can afford it, buy US made. It will cost now but it's worth it! I like the look of Dotco, which I see more and more in the aviation industry, but there are others!
Mid range is probably Kuken. Japanese made (except the very cheapest) and by all accounts quite good!
Failing that, get a used good quality tool! Here in the U.K. I can usually get a used Desoutter (British made) of whatever I want if I wait long enough!
For many years the IR die grinder was pretty much industry standard in the U.K. All but the cheapest in the range were US made, and decent quality too!
Sadly, over the last couple of years that's changed! Aside from being made god knows where, IR havn't attempted to even make the same tool any more! The current offerings all seem to have loads of plastic - and I refer you back to paragraph one in that regard!
So, what to do? If you go down the Taiwanese route, don't believe all the shite the manufacturers, correction importers, come out with such as "it's made in 'our' factory in Taiwan, to 'our' standards"! It will be made in the same factory as all the others, to the same standard! The only thing that will vary is the price, so buy the cheapest!
An example, I recently looked at air files! Snap On have got their Blue Point on a special offer for, I think, about £160 at present! I can get the same tool (exactly the same tool, but painted red not blue, for £40 elsewhere!
If you can afford it, buy US made. It will cost now but it's worth it! I like the look of Dotco, which I see more and more in the aviation industry, but there are others!
Mid range is probably Kuken. Japanese made (except the very cheapest) and by all accounts quite good!
Failing that, get a used good quality tool! Here in the U.K. I can usually get a used Desoutter (British made) of whatever I want if I wait long enough!
Is the Composite body Dotco's (12 LF series) any good or should I be looking at the aluminum body (10LF series) for Dotco die grinders?
Since I have a bit of time to wait and watch ebay I was hoping to find something in really good condition for a great deal, then if need be get a tune-up kit and still be around the same price range the IR 5102 MAX grinder.
Since I have a bit of time to wait and watch ebay I was hoping to find something in really good condition for a great deal, then if need be get a tune-up kit and still be around the same price range the IR 5102 MAX grinder.
Ign
Well-known member
I think a 45 gal compressor is borderline, which means you'll hate your life w a bottom dollar Chicom because they are air hogs. Get a lower HP brand name unit for the best shot at efficiency. Honestly one of my favorites is my right angle IR, 301 or 302 I think it is?? But likely not US made anymore? My right angle Astro Pneumatic is also nice, but definitely Taiwan.
MSC always has the Sioux stuff featured, right now right angle is $80, part ED33009499 at mscdirect.com. Have it tomorrow at ground rates. Not sure of COO tho.
If you're doing mostly gasket prep, this is an area where cordless is starting to intrude - or at least trying - check out the Milwaukee 2438-20. Would probably only make sense for you if you're already into M12.
MSC always has the Sioux stuff featured, right now right angle is $80, part ED33009499 at mscdirect.com. Have it tomorrow at ground rates. Not sure of COO tho.
If you're doing mostly gasket prep, this is an area where cordless is starting to intrude - or at least trying - check out the Milwaukee 2438-20. Would probably only make sense for you if you're already into M12.
If you are not familiar with air tools, you have to be careful with IR, CP, and Sioux. They make both industrial grade and home owner grade air tools. You think you might be buying an industrial grade tool and end up with home owner grade tool. Brands like Dotco, Cleco, ARO, Atlas Copco, Desoutter only make industrial grade tools. Dotco die grinder is designed more for fine detail grinding and polishing. Also, some Dotco are oil free meaning it is designed to run dry (no need to add oil). If you want heavy duty grinder for removing a lot of material, you may want to check out Cleco. Cleco is heavier as it's body is made of steel whereas Dotco is made of aluminum with steel shell inside. Cleco is expensive though.
ZRX61
Well-known member
Just stay away from anything that has plastic gears. The Matco I bought crapped out after 2 weeks.
sberry
Banned
I have a lot of air stuff but probably not a "die" grinder as you are thinking, didn't look at the models but the only ones anymore that are truly cheap are the 9$ HF pencil grinder and even that is disposable and they actually last a long time.
I use a wire wheel on a right angle got gasket work, I got a few of the 3m things but really don't use them, not that they are not good, just have other stuff I like just as well.
I don't agree that the cheap tool is an air hog over any other, they have been good for a long time.
Some of those Central air tools are really good. Here are 3, more use than a hobby guy would ever give them, I did put a bearing, was a common one I had in stock in the head of the large sander but that was well after the tool would have been depreciated over and over. I can recall buying several boxes of disks when I was busy. It still works good, it uses some air but its a big tool.
Same for the right angle 4 inch. I got one that has hundreds of hours on it, still works perfect, not so much as a loose screw.
I use a wire wheel on a right angle got gasket work, I got a few of the 3m things but really don't use them, not that they are not good, just have other stuff I like just as well.
I don't agree that the cheap tool is an air hog over any other, they have been good for a long time.
Some of those Central air tools are really good. Here are 3, more use than a hobby guy would ever give them, I did put a bearing, was a common one I had in stock in the head of the large sander but that was well after the tool would have been depreciated over and over. I can recall buying several boxes of disks when I was busy. It still works good, it uses some air but its a big tool.
Same for the right angle 4 inch. I got one that has hundreds of hours on it, still works perfect, not so much as a loose screw.
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sberry
Banned
You already have an undersized comp, a pinch here or there wont mean squat. We are back to the same equation we are with the hand tools today. Walk up and down a flea market isle a few times, pass thru a box store and see whats on the shelf. They always make an uber cheap model but the one step up version like I have in those pics are great. They are a mass produced clone at 1/4 price maybe.
Unless we are talking a specialist and maybe even then I bought when I really needed it and it has fallen back to the maintenance level you only use it when needed. I would buy a little selection or as we did redundant with the 4 inch but that pencil unit in my pic above was from HD, I should have got another one but I got specialty bits or wheels on some old ones, the wear and tear goes on the China.
Nothing beats the 4 inch on rust work. One of the others has a small heavy knotted wheel on but the Lions share goes to the right angle. I would have traded compressor for quality of tool if I was going to do hard assed work.
Unless we are talking a specialist and maybe even then I bought when I really needed it and it has fallen back to the maintenance level you only use it when needed. I would buy a little selection or as we did redundant with the 4 inch but that pencil unit in my pic above was from HD, I should have got another one but I got specialty bits or wheels on some old ones, the wear and tear goes on the China.
Nothing beats the 4 inch on rust work. One of the others has a small heavy knotted wheel on but the Lions share goes to the right angle. I would have traded compressor for quality of tool if I was going to do hard assed work.
ttpete
Well-known member
I have Dotco all the way from pencil size up to a 5 inch angle grinder. The rear exhaust models are quieter because the air exhausts through a sleeve surrounding the air hose. They're kind of the Cadillac of air grinders.
I also have an Aro turbine type 1/8" grinder that cranks up 85,000 rpm. It's too fast for any type of mounted stone and is used with carbide burs only.
Any Dotco recommendations for what I'm needing? I was thinking something along the line of a 0.3 or 0.4 HP 20,000 RPM unit in either composite or aluminum body. Think the aluminum body is suppose to be a bit more rugged, but I'm sure a composite body industrial grade tool will hold up to my home use. Just out of curiosity what is the differences between the 200 series and 300 series collets?
Guess I need to dig more into SCFM requirements of various grinders, probably pointless to get a cadillac if I can't power it adequatley.
Guess I need to dig more into SCFM requirements of various grinders, probably pointless to get a cadillac if I can't power it adequatley.
AndyA
Well-known member
I have IR, mac tools, and dotco. The IR and mac tools are comparable, but the dotco is way better. For the same HP rating the dotco seems to have more balls. The IR cut-off grinder will get hot (too much drag in the bearing?). You have to re-oil every 10 minutes or so to keep it cool. The dotco gets colder the harder you push it. I run these with an inline oiler.
If you plan on using cut-off wheels, watch out for the speed ratings. Most wheels I buy are rated for 25000 rpm, but some are not. If you get a lower speed grinder you won't have to watch what wheels you buy.
I'd go ahead and buy top quality air tools. You can run them on an undersized compressor, but you'll have to wait for the compressor to catch up. You'll probably be upgrading your compressor at some point in the future. Why re-buy the air tools later when you have a good compressor. Just buy them now and be done with it!
If you plan on using cut-off wheels, watch out for the speed ratings. Most wheels I buy are rated for 25000 rpm, but some are not. If you get a lower speed grinder you won't have to watch what wheels you buy.
I'd go ahead and buy top quality air tools. You can run them on an undersized compressor, but you'll have to wait for the compressor to catch up. You'll probably be upgrading your compressor at some point in the future. Why re-buy the air tools later when you have a good compressor. Just buy them now and be done with it!
chris142
Well-known member
Get a reversable one. Nothing worse than getting sparks thrown on you due to a position you must be in. I recently bought a Matco one but it's made in Taiwan so its not on your list.
softailgarage
Well-known member
I can't believe I'm recommending this but... I use a right angle die grinder a lot. I have Craftsman, Snap On, Matco, & IR. Know which one is best? The one I paid $8.00 for a couple of years ago at ...Harbor Freight. Yep, kicks the **** out of Snap On, hell, even the Craftsman is better than SO.
There you go, the ONLY tool I'll ever recommend from HF
There you go, the ONLY tool I'll ever recommend from HF
Wamsutta
Well-known member
That depends on what you're going to be turning with it. Each abrasive disc has it's own speed rating depending on its diameter. Figure out what you're going to be turning with it and then you can more easily decide on an RPM.
From searching here looks like maybe the 2" Roloc abrasive discs and scotch-brite pads is most common and I'd imagine allows one to get into tighter spaces. So maybe I should look at 20,000 RPM models.
Was looking into the CFM ratings of various die grinders. Found the ratings nicely laid out on Grainger's site. Do these Dotco 12LF or 10LF series ratings sound right: 2.75 ave CFM / 11 CFM at load for rear exhaust and 2.25 / 9CFM for front exhuast??? Dynabrade, IR (industrial and non-industrial) and Chicago Pneumatic industrial CFM ratings for similar size grinders where all pretty much double the Dotco ratings. Are Dotco's really that efficient or do they use a different testing method to make their numbers look better?? If this is really the case then my 10.1 SCFM compressor may not be too under-sized. But take into account factors such as air fittings, flow restriction thru the air hose, etc and it's doubtful there's 10.1 CFM at the tool.
rcjoy
Well-known member
Regarding SCFM rating of your compressor, that's just the rating of the pump (continuous SCFM).
If you use the tool for short periods of time (limited by your tank size), your actual available CFM at the tool is much larger. A Milton M-style air fitting supports about 40 SCFM, the V-style is over 70 SCFM.
If you use the tool for short periods of time (limited by your tank size), your actual available CFM at the tool is much larger. A Milton M-style air fitting supports about 40 SCFM, the V-style is over 70 SCFM.
byoungblood
Well-known member
I have a 10 year old composite Campbell Hausefeld that has worked well. Only issue is that like any of them, it takes a lot of air, and my compressor can only run it at full speed for maybe a minute or two before the pump kicks on and doesn't keep up. So if I'm doing something that requires more than a moderate load I'm usually stopping and waiting for the tank to pump back up.
I'm gonna be a negative nancy here and actually say don't waste your money....just go get one or two hf ones and be done with it. I can honestly say this was one of my first hf buys and I've had it for atleast 10 years. I don't even recall the last time I oiled it because it's so cheap I just don't care. It always works flawless tho when I need it
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sberry
Banned
With a little restriction there is some pressure drop but you can get 10 cfm to a tool by opening the valve. The object here especially since its not free huge plant type unlimited air isn't to see how much you can dump thru the tool but to get the best use from what you got.
A little restriction and pressure drop help reduce waste especially on start up, no point in seeing how much air one can blow thru it but to convert this energy to work. Nothing about air tools are efficient, about 20% or so give or take is likely but the idea is to replace or utilize valuable manpower.
A good example is common grinding. Since the wheel cost the same you can put a 4 1/2 on a 30$ Walmart grinder and run it weeks for 15 cents an hour in power or can use an air unit that cost 100$ ran buy a 2K compressor plus maintenance and a dollar an hour in power. Does the same work essentially.
We like air on wire wheels as the duty cycle is relatively low and the power is so variable and the mechanic is 50 times as valuable as the tool so we want the work done good and fast.
Hence buying a few more tools soon pays off due to the man not having to change wheels for a different operation. Lots of guys here have 3 or 4 power units,, or more. Grinding, flap wheel, wire etc.
I am not sure how eaxh co comes to their conclusions but you can bet its a best case scenario and you wont notice a night and day difference.
ZRX61
Well-known member
I agree, I have a few of there $8 grinders, thought I'd just toss them when they broke... had them for years....I'm gonna be a negative nancy here and actually say don't waste your money....just go get one or two hf ones and be done with it. I can honestly say this was one of my first hf buys and I've had it for atleast 10 years. I don't even recall the last time I oiled it because it's so cheap I just don't care. It always works flawless tho when I need it
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Hammer1963
Well-known member
Just buy a Snap-on 300 series .5 HP and it will last forever.
wafrederick
Well-known member
I have a couple King Tony of America die grinders,been holding up for me.I did buy a 120 degree Central Pnuematic from HF,had to exchange the first one I bought for another one.Leaked air out of the speed adjustment valve out brand new out of the box.The replacement is much better,no problems yet and not bad for $27.00.