What size angle grinders

[Hagatronics]

Hi All

I'm about to do some light fabrication of some steel frames etc (e.g up to 50mm hollow tubing) and want to pick up a few angle grinders. I'd like to have three grinders all-up so I don't have to change disks too often between grinding, cutting and a flap disk. I'll often do other light work (auto body, light fabrication etc) and weld with MIG and TIG.

My question is what size & min power angle grinder would you recommend for these three operations?

On what basis would you buy 4, 4.5 or 5 inch grinders? Is a larger 6-7 inch better for cutting?

I already have a 100mm (4") 500W Ryobi grinder - it's old, cheap, low power and doesn't have a spindle lock but worth keeping in the mix.

I'll probably buy Makita or Metabo but I'm more interested in your views on disc diameter and power for these three tasks.

 

[MJD1]

I use a 6" size, metabo and dewalt, for 95% of what I do. The extra diameter is a huge benefit for cutting. To me it's a good trade-off between the 4.5" and a 9". I do use a 4.5" for flap discs, mainly for the economics on 4.5 vs6" cost.

 

[Engine]

Bosch or Makita grinders in 4.5 in. disc size and 6 amp. will do the job. They both have the power to cut, grind, and sand without being too heavy. In light fabrication, I don't think it is likely that you will use a larger one much unless you have some thick plate to bevel or cut. You may be able to find a deal on a pair of the above grinders for under $100 US.

 

[BK13]

Metabo or Fein, 4.5", if you were in the US, but I don't know what's common in OZ. 8-10 amp. Maybe one 14ish amp 5" model.

 

[Wamsutta]

I think the 6 inch is the most useful. It gives you a pretty big disc, yet the grinder body is still the size of a 4.5 inch grinder. Just my preference.

 

[Hagatronics]

Metabo or Fein, 4.5", if you were in the US, but I don't know what's common in OZ. 8-10 amp. Maybe one 14ish amp 5" model.

Would you use the 5” more powerful one for cutting mostly?

 

[AJ.]

I have 2 @ 5" Makita Grinders, one with a cutting disc and one a grinding disc. Also 2 x 4.5" Hitachi grinders, one with a flap disc and one with a wire wheel. That combination works well for me.

I would get a 7" if doing heavy work but no bigger, 9" grinders scare the living day lights out of me.

Cheers Andrew

 

[Mattpopp]

I love my 4.5 makita. But you need to buy the higher end version. Otherwise you are just throwing money away.

 

[Mattpopp]

Hilti is another great brand

 

[bob15]

I have a 5" and a 9" Metabo and won't buy another brand again. Their grinders are so smooth and comfortable to use, I am actually amazed.

You can find decent used Metabo's on e-bay

 

[sam.coll]

Would go 125mm, 1100W to 1400W for grinding, have 3 Makitas but will go Metabo next. I prefer the rat tail with paddle switch for heavy/prolonged grinding work,

http://www.makita.com.au/products/p...mm-angle-grinders/ga5021c-125mm-angle-grinder

 

[Dave455]

Only advice I'd give, if you're considering 3 angle grinders (and I can see why you would) is to also consider something like a a Fein Multimaster.

I bought one a couple of years back for basically one job, and I now use it so much it's probably my second most used power tool!

Most surprisingly, I seem to use it most often instead of an angle grinder! They're a stack safer to use as you havn't got a high speed disc, they're quieter to use, and they don't chuck dust and debris everywhere so at the end of a day you are a lot less fatigued! Blades can be changed in seconds without tools too!

O.K. a really big grinder probably has no equivalent in the Multimaster world, but I hardly use my small grinder now!

 

[IndyGarage]

I have about 12 grinders in 4 1/2, 7 and 9 inch. 90% of the time I use the 4 1/2 inch ones.

The big ones are just too heavy, bulky and powerful to use for more than a few minutes at a time. If I need to run a big knotted wire brush or a big flap disc I'll use one of the big ones.

As far as brands go, I like Makita and Metabo best. Makitas run the smoothest. The Metabo with the quick nut is really convenient.

Bosch makes one with a thinner barrel which is really nice to hold , but it's rough and noisy and a bit down on power.

Porter Cable makes one that is relatively cheap and really durable.

As far as power - any of them will run a flap disc, grinding wheel or cutoff wheel. The real power hog is a wire brush. I know it's dangerous, but I often run a 7 inch cutoff wheel in a 4 1/2 inch grinder and most of them have no trouble pulling it.

One more thing - I've learned to use safety gear when running a grinder - I normally wear a leather welding jacket, a full face shield, welding gloves and ear plugs. I'm still healing from a burn where a stream of sparks from a grinder burned right through a padded pair of mechanix gloves and burned a spot on the back of my finger.

 

[Tim37]

You can buy 4.5" disk anywhere.

 

[jeeper46]

Let me add the voice from the cheap seats here: I have four HF 4 1/2" grinders, each with a different wheel on it. I've never had one fail, and they have had plenty of power to do what needs to be done. I do have a Milwaukee and an older Craftsman too. It's so much more efficient and time-saving to have dedicated grinders, instead of changing wheels all the time.

 

[Cope]

For lighter work I have two DeWalt 4.5" grinders. I also have a 5" DeWalt and my beast is a big Milwaukee 7/9" that I use with 7" wheels. I only use it for heavy work, I keep one 4.5 set up with a wheel and the other with a flap disk.

 

[bcradio]

4.5" or 5" will be what you want here.

My one bit of advice would be that you get at least one of the three grinders with the variable speed option. They are more expensive, but very useful at times.

I have a Bosch 5" variable speed that was made in Germany and that works great for the times I need to reduce the speed. Makita and Matebo also make variable speed grinders as well.

 

[MrGiggles]

If you cut a lot of tubing, a 7" grinder will work a lot better. After the wheel wears down some on a 4.5", you only have an inch or so to work with. That being said, a chop saw is a heck of a lot better than a grinder for making cuts through tubing.

 

[manufacture]

I prefer 4.5 inch angle grinders as being able to one hand them on occasion is helpful. I have a dewalt 4.5" paddle switch 10 or 11 amp model I have had for years and was my only grinder for a time so it saw heavy use. It has never let me down. Since I wanted to stop playing the wheel switch game I recently bought a pair of Makita 4.5 inch 7.5 amp slide switch grinders. They are smoother and more quiet than the dewalt and I haven't noticed the difference in power yet. I don't know if you have the same deal in Australia but I was able to get the pair of makitas as a package for $100 USD. I am sure the Metabos and Feins are great grinders but since I am using my grinder mostly as a hobby, getting two good grinders for less money than one great grinder seemed to make more sense to me.

 

[skipnay]

I prefer the 4/4.5 over everything else. Every time I have used the big 9''(friend let me borrow) after using it for a couple seconds I needed a smaller one to fit in areas. Though here of late a big one might come in handy.

Just don't buy the 24 grit flap disc. They seem to wear faster then the 60's. Even though the 24 takes it off faster I can get more done with the 60 grit. I haven't tried the 40 grit flap disc yet. I get my stuff from Lehigh Valley Abrasives, they have good quality stuff. I even got to many 24 grit instead of 120 grit once and they told me to keep the 5 pack of 24 grit and sent me my 120 grit!!! All I wanted to do was make another order and they definitely took care of me!

 

[zkling]

I'd get two 4.5 and one 7 or 9". The 7/9 works great for large surfaces, but the main users will be the 4.5".

 

[BK13]

Would you use the 5” more powerful one for cutting mostly?

I find cutting (death, LOL) wheels pretty fragile. I crank on my grinders pretty hard, when I'm grinding. That's where I'd use the bigger one.

 

[crewchief888]

i grab a 4 1/2" grinder before anything else.

i have 4 or 5 electric, 1 air powered, and a milwaukee fuel 18v cordless.

 

[Pitalplace]

I have two of the DeWalt 5" and love them. More horse and a little more cut in the smaller size. Five inch wheels are not the easiest to find but you can also use the 4.5

 

[PBCampbell]

4.5" here. I upgraded to Makita's a few years ago and really like them. I have 3 in the arsenal. Two with regular lock-on switches and one with the paddle switch. The paddle switch sees brush duty exclusively, as when the brush catches it shuts off with a simple hand release.
Something I can't remember ever seeing here is to rotate the gear head to serve the grinder's primary use. This is especially important with lock-on swithes, so the "off" switch is in a convenient location for use, under the thumb.

 

[Ericgst]

I don't like the small wheels on a 4.5". The 5" wheels are only 1/2" bigger but it makes a huge difference.

I have two 5" grinders and two 6" grinders.

The 5" can use 4.5" discs so they are more versatile, the 6" grinders are much more powerful without getting too crazy like the 7" and 9" ones.

 

[md21722]

I have a half dozen 4-1/2" angle grinders. Both the grinders and wheels are readily available locally if you run out and need something quick. 6" is a rare breed locally. If you have larger surfaces 7-9" would be a win but they are beastly if they're electric and use ungodly amounts of air if they are pneumatic. Think 25 HP air compressor. It's for shipyards. A buddy of mine was thinking of getting a 6" and I suggested he go down to the local Home Depot and look at them. He bought a Metabo 4.5" online and called it good.

 

[Ign]

Metabo or Fein, 4.5", if you were in the US, but I don't know what's common in OZ. 8-10 amp. Maybe one 14ish amp 5" model.

I can't fathom how or why you'd ever need or want 14amps in a 5" grinder. That's like holding a 14" abrasive chop saw or 12" miter saw in your hands but using a 5" wheel.

I do have a 12A Milwaukee 4.5", but it seems overkill.

Does anyone even actually produce a 5" 14A angle grinder??

An 8A Metabo will torque you around just fine, not sure why anyone would want more with the exception of wire cup brushes which place a lot of drag on grinders.

 

[Cope]

I can't fathom how or why you'd ever need or want 14amps in a 5" grinder. That's like holding a 14" abrasive chop saw or 12" miter saw in your hands but using a 5" wheel.

I do have a 12A Milwaukee 4.5", but it seems overkill.

Does anyone even actually produce a 5" 14A angle grinder??

My DW831 (pictured) is 12 amps.

My 7/9" Milwaukee is only 13 amps, but it is one **** kicker.

 

[AJ.]

An 8A Metabo will torque you around just fine, not sure why anyone would want more with the exception of wire cup brushes which place a lot of drag on grinders.

A wire cup is one instance where I think less power is better, they are prone to grabbing and become incrementally more dangerous as the power of the grinder increases.

Cheers Andrew

 

[BK13]

I can't fathom how or why you'd ever need or want 14amps in a 5" grinder. That's like holding a 14" abrasive chop saw or 12" miter saw in your hands but using a 5" wheel.



I do have a 12A Milwaukee 4.5", but it seems overkill.



Does anyone even actually produce a 5" 14A angle grinder??



An 8A Metabo will torque you around just fine, not sure why anyone would want more with the exception of wire cup brushes which place a lot of drag on grinders.

Maybe I'm using it wrong, but I can pretty easily stall out my 8-1/2ish amp 4.5" grinder. My Fein 5" is somewhere around 13-14 amps, but it doesn't seem like it's going to run away from me.


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[sberry]

4 1/2 for general work.

 

[Monte]

5" for increased cutting depth compared to 4.5".

 

[Playwme]

For cutting I use a 5 inch Makita. Nice and light, good feel and power, and it doesn't kick too much on startup. Just got a Metalmaster 9 inch cold saw though so the Makita now does a lot less than it used to.
Most other stuff I have a pile of 4 inch XU1's from bunnings. They were about $20 each when I got them. All of them still work no problems.

Also have a 9 inch Makita. Heavy and awkward and I don't use it for much more than pavers and concrete now. It's got grunt though if you really need it.

 

[David0858]

georgegj

Let me add the voice from the cheap seats here: I have four HF 4 1/2" grinders, each with a different wheel on it. I've never had one fail, and they have had plenty of power to do what needs to be done. I do have a Milwaukee and an older Craftsman too. It's so much more efficient and time-saving to have dedicated grinders, instead of changing wheels all the time.

I've used and abused HF 4 1/2" grinders for years and have yet to have one fail. Even the two $9.99 ones I've ran until they were too hot to hold, let them cool off enough that I could hold them then went after it again. If I used them commercially all day every day I might feel differently but with these I can afford to have grinder set up for every purpose.

 

[Know Wosad]

When I open in the morning I generally grab a Bosch slim 4 1/2 and a 5" Metabo and head to the welding bench with them.Theres a couple others, as needed
That large black on the left is an interesting piece. A Skil 9". Light as hell for its size.
Picked it up in Juarez. $110. 2 year guarantee

VID
https://vimeo.com/6091432

 

[BK13]

Huh. My Bosch Slim almost made me swear off other Bosch tools.


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[1badbird]

I recommend a couple of 4.5" and 6" Metabo all the way.

 

[BK13]

Re: georgegj

I've used and abused HF 4 1/2" grinders for years and have yet to have one fail. Even the two $9.99 ones I've ran until they were too hot to hold, let them cool off enough that I could hold them then went after it again. If I used them commercially all day every day I might feel differently but with these I can afford to have grinder set up for every purpose.

Pretty sure the OP ain't gonna jump on a plane for an HF run.... LOL


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[Hagatronics]

Re: georgegj

Pretty sure the OP ain't gonna jump on a plane for an HF run.... LOL

You never know

Pretty sure I'm going to grab
- two 4.5" Metabo's 850W one each for grinding and flap disk
- one 5" Metabo 1010W for cutting

Will use my old 500W Ryobi for wire wheel

I can't find a 6" for the life of me and 7" seems too big for my needs.