7" angle grinder

[ning]

I'm quite the amateur and I'm wondering at what the 7" (and 9"!) grinders are typically used for.
I've got three 4 1/2" grinders that get a lot of use, but I've never been exposed to a 7" and I tend to make do with what I've got unless it flat-out doesn't do the job, or someone educates me, and since my old mentor-neighbor died a while back, I don't get much of an education other than what I get off the web.
So, web, tell me why I need a 7"

 

[spitter]

How much material u want to remove and how much power u need are some good reasons for going from a 4 1/2 " grinder to a 9". 41/2 are usually 4 or 5 amp 9 " are 15 amp . Go on the metabo website and look how many grinders they make ranging from lite duty 7 amp to 14 amp .In all sizes 4 - 9 , you wouldn't want to use a 14 amp 5 " grinder made for concrete diamond wheels to remove rust or paint all day . The weight difference is a few pounds between 7 amp and 14 amp. If u put a diamond wheel in a 4 1/2 " 7 amp grinder and tried to cut concrete it wouldn't last a day. Match grinder power to job. :drink:

 

[Bird]

I'm quite the amateur and I'm wondering at what the 7" (and 9"!) grinders are typically used for.

I'm not sure exactly how they were used, but the Sioux tools I dealt with were very old and were used by one of major trucking company's "trailer rebuild shop".

 

[Soggy Bottom Outdoors]

No real agreement here. But I've used a lot of Dewalt stuff and had good service. Lookin' at model DW840 I think. I also have several Bosch tools, like a sawz-all, that has gone above and beyond. Lookin at model 1974-8. About a $60 price difference. Mostly used on old broken farm equipment farm equipment.

 

[Fallon]

I got my 9" HF to finish a cut through concrete that was thicker than expected. Didnt want to rent a real concrete saw & needed the bigger blade for an inch or 2 more cutting than what I got out of the diamond blade on the circular saw.

Use it for bigger grinding jobs on steel mostly now.

 

[Sebculb]

I'm quite the amateur and I'm wondering at what the 7" (and 9"!) grinders are typically used for.
I've got three 4 1/2" grinders that get a lot of use, but I've never been exposed to a 7" and I tend to make do with what I've got unless it flat-out doesn't do the job, or someone educates me, and since my old mentor-neighbor died a while back, I don't get much of an education other than what I get off the web.
So, web, tell me why I need a 7"

I don't actually use the big grinder for that much metalworking. 9" diamond blade is terrifying but works well for cutting concrete and rock.

Put a sanding disc on it for fast wood removal sanding in rustic carpentry. Belt sander can't compare. Belt Gives cleaner results but three days into sanding a new cabin out in the woods you might reach for the disc.

And sometimes with metal, for big metal or a lot of metal or a lot of grinding, the bigger tool is faster and takes the abuse better.

I have a DeWalt 9", put 7" on it sometimes. 9" is lower rpms so better for sanding wood and the bigger blade capacity is good for concrete. Works well, good quality so far.

 

[dragoneggs]

I still crack up when I read Hp ratings. The Bosch may be the cat's meow but they advertise 4hp. Huh??? I love Bosch but com'n man!

120v machine at 15amps is 1800watts. Equals 2.4hp. Please explain.

1974-8 | 7 In. 15 A High Performance Large Angle Grinder | Bosch Power Tools

 

[Redlands Okie]

Got a Milwaukee that has ground a LOT of concrete floors the last couple of years and a fair bit of metal. Holding up nicely.
Dewalt would be my second choice of brands.

Matebo, Bosch, Mikita all are known good brands

 

[stuckmotor]

Has anyone ever used the replacement brushes that come with the power tools? If I have, it was only one time and I don't remember for sure.

 

[searcyfarms]

yes I have on my 4 inch grinder - easy to replace and away I went!!! as for the hp ratings, you can put in a bigger motor to handle more stress and rate your tool higher to sound better but it doesn't mean you are getting that much power just that it has that big of a motor - kind of like a 150 hp tractor in soft ground you wont get the pull you do in dry dirt but the motor is still putting out the same power

 

[searcyfarms]

and back to the original - I have a good friend that is a welder and he uses Milwaukee, bosch, Makita, and he recommended I go with the dewalt that uses the old B&D patent that they bought out, they are a heavy beast and he grinds a lot on bridges and gets a lot of dust so cooling/air circulation and how the dust is pulled through the motor and design are also a consideration, I have no clue what the differences are in each particular model but he says his last two dewalts have lasted longer than the others of ANY brand so he has been buying those - he wears one out about every 8 to 10 mos and has been getting close to 2 yrs out of the dewalts - they use them for cutting and grinding and they will hurt you if you are not careful, when one of those wheels catches it will pull you into your work etc......not for the weak operator or faint of heart - I use mine for mostly metal work and its been great so far

 

[Billself]

FEIN is one of the best i've ever used great service great warranty great tool different sizes to suit your need. been using mine for years without problem and i use mine a lot . i've tried other brands dewalt milwalkie ryobie craftman but FEIN has outlasted all of them. hope you find a good grinder

 

[Thomas]

I like my Milwaukee most of all the hand grip.

 

[ning]

I still crack up when I read Hp ratings. The Bosch may be the cat's meow but they advertise 4hp. Huh??? I love Bosch but com'n man!

120v machine at 15amps is 1800watts. Equals 2.4hp. Please explain.

It's only 2.4hp at 100% efficiency, which is unlikely (ie impossible; 60-80% is more likely).

4HP is probably right before the motor stalls, when it pulls so much current that if you didn't have it on a breaker, the motor would smoke and your wiring would catch fire. Obviously, not a sustained hp number!

 

[TMGT]

Can honestly say I never pay attention to the hp rating on hand tools.

 

[patrick_g]

I have a corded 7 inch Milwaukee and it is terrific, great power. It is a handful but is a glutton for hard work. B&D and DeWalt are both made in the same factory and are several notches down below the Milwaukee.

 

[searcyfarms]

Patrick Patrick Patrick.............regarding your signature..........I grew up raising hogs, I have wrestled many and was never out done, however I never took on one I didn't think I could whoop - the worst were the reds/duroc mother with babies or the free ranging Berkshires - they were the biggest sows ever, managed to stuff 3 sows in our 1975 ford pickup and they avg'd over 825lbs each, it took some big lumber and time to get those three loaded.

as for having all the fun, not sure if they still have them but we had greased pig races at all the country fairs around - I had so much fun winning them, you NEVER grab a hog it will get away, you always jump on them and mash them into the dirt, bear hug him with an arm load of dirt as you scoop him up.................then run for the finish line!!! I won a lot of spending money back in the day doing that and had so much fun so I know first hand those pigs didn't have all the fun - such great memories - thanks for reminding me!!!!

 

[patrick_g]

A big Poland-China could be "fun." Any way, just in case, my signature is metaphorical, not literal.

 

[searcyfarms]

ahhhh yes the good ole spotted Poland-china girls...........we had some of those as well - we ended up mainly with hamp and york cross - long and beefy hogs with great loving temperaments - more safe for us kids doing chores - although with 3 sisters and no brothers I did 90% of it unless I needed help, hence when I left home they got rid of all the hogs within 1 yr ;-)