7" angle grinder

searcyfarms · Aug 24, 2018

thinking about it, maybe a 7" grinder would have worked well on the tusk/tooth extraction rather than pliers and a hammer !!!!

yomax4 · Aug 24, 2018

stuckmotor said:
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.

I've replaced brushes in Milwaukee 4.5" grinders, Drills and Worm gear saws. It's nice to be able to do that But.. The new cordless-brushless tools are amazing.

two_bit_score · Aug 24, 2018

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

It is the amps that count.

TMGT · Aug 24, 2018

Re: 7" angle grinder

two_bit_score said:
It is the amps that count.

Yup, typically only look at amps, rpm and weight on grinder specs.

DXN1EL · Aug 25, 2018

They neet to come out with a real 7 0r 9 AC brushless.
The small frame ac brushless seem nice

al3 · Aug 25, 2018

Got a 7 inch Milwaukee in 2005 primarily for the extended reach over a 4.5. Gets into deeper corners/cuts deeper than the smaller diameter wheels.. That said, I make a mental note to concentrate hard when using the thing. The starting torque is significant (compared to the smaller ones) and if the optional hand grip is not attached, thing want to twist in your hands. Everything else is also magnified, so if it binds and kickbacks, it pays to be on your toes. If you like running these with the guards removed, pay particular attention.

Thing has some heft to it, will build up your forearms with repetitive use. Any position other than horizontal is a workout, at least for this old guy. I use it, but not nearly as often as I thought when purchased.

MinnesotaDaveChalmers · Aug 25, 2018

al3 said:
Got a 7 inch Milwaukee in 2005 primarily for the extended reach over a 4.5. Gets into deeper corners/cuts deeper than the smaller diameter wheels.. That said, I make a mental note to concentrate hard when using the thing. The starting torque is significant (compared to the smaller ones) and if the optional hand grip is not attached, thing want to twist in your hands. Everything else is also magnified, so if it binds and kickbacks, it pays to be on your toes. If you like running these with the guards removed, pay particular attention.

Thing has some heft to it, will build up your forearms with repetitive use. Any position other than horizontal is a workout, at least for this old guy. I use it, but not nearly as often as I thought when purchased.

The 9" I have has "soft start" - it's a nice feature for sure with a 15 amp motor.

It's fairly heavy, flat position grinding is its preferred use

patrick_g · Aug 25, 2018

Horse power, if reported accurately would be a terrific figure of merit for rating/comparing grinders and such. Amps alone represents a questionable figure of merit as it does not take into consideration efficiency. A very inefficient tool might use lots of amps but much of the power consumed could be going to heat, not torque. You might have noticed really cheap poor tools often run hotter than high quality tools. That is more electrical energy going to heat than useful work as compared to the high quality tool.

dragoneggs · Aug 25, 2018

patrick_g said:
Horse power, if reported accurately would be a terrific figure of merit for rating/comparing grinders and such. Amps alone represents a questionable figure of merit as it does not take into consideration efficiency. A very inefficient tool might use lots of amps but much of the power consumed could be going to heat, not torque. You might have noticed really cheap poor tools often run hotter than high quality tools. That is more electrical energy going to heat than useful work as compared to the high quality tool.

Good point!

Texasmark · Aug 25, 2018

Soggy Bottom Outdoors said:
My old 7' angle grinder finally died after many years of good service and a replacement is needed. What brand/model/features do you like? I have a 4 1/2 inch one, but need the bigger model. What do you have?

All mine are HF and are super products for the price. I like the 4 ｽ grinders running 4 amps which have a really attractive price. I have their 9" and it's a beast. 7 would be a good size for larger jobs as the beast is just that. However, for most jobs the 4 ｽ does the job...I have 4, 2 older ones and 2 newer ones, all still working. 2 have grinding wheels, one regular grinder and the other something new that is a series of strips of abrasive glued around in a circle for knocking rust off things you don't want to cut into, one with a cutter wheel, and the last with a wire brush. For dressing mower blades they can't be beat and on my shredder, i just lift up the shredder, roll the blade around to where I can get to it from the rear and in a flash ready to go.

big bubba · Aug 25, 2018

patrick_g said:
Horse power, if reported accurately would be a terrific figure of merit for rating/comparing grinders and such. Amps alone represents a questionable figure of merit as it does not take into consideration efficiency. A very inefficient tool might use lots of amps but much of the power consumed could be going to heat, not torque. You might have noticed really cheap poor tools often run hotter than high quality tools. That is more electrical energy going to heat than useful work as compared to the high quality tool.

there's so much more than raw power to a grinder. longevity weight safety features soft start ergonomics, etc.
as the years pass, i prefer a more refined tool w/additional qualities mentioned above as well as the sheer power that you mention. sometimes lighter weight alone is an added safety feature.

DXN1EL · Aug 25, 2018

Highly recommend Metabo W24-180.

stuckmotor · Aug 25, 2018

On one project, I had two or three of those low power 4 1/2 inch grinders going (probably not all Harbor Freight). One would cut until it got too hot then cool while another took it's place. If I remember right, I burned one of those little ones up before I realized I could buy cutting blades for the 9" grinder. The gyro effect of that 9" grinder used to tire me out pretty bad.

California · Aug 26, 2018

I bought the HF 9" angle grinder the year I had Inside Track special pricing and I just couldn't pass it up.

But I learned it's a tool for someone athletic. I used to work construction 40 years ago but now the thing is too much of a monster, I don't feel safe running it in awkward positions. I sold it.
Here's a post with photos where I hogged out cast iron to modify some wheel weights.

I bought HF's 7" angle grinder to replace the 9". Running a DeWalt disc, that meets my needs for a larger grinder.

But the HF 4.5" grinders with flap disc, grinding disc, wire brush are used more often. At 6 amps or less they aren't as powerful as a pro tool but I'm not in a hurry.

Texasmark · Aug 26, 2018

dragoneggs said:
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

The current craze of telling you that you are getting something when you aren't is to take the object and hook up oscilloscopes to the voltage and current. Get it in a clamp so that you can severely restrict the movement of the shaft. When the voltage starts falling and the current starts rising, the highest product observed during that exercise is the "rated" hp. Few do it but some folks also post the full load running amps which gives you the true picture of the items usefulness.

I have a 60 gallon air compressor with an advertised 6.5hp motor in big letters on the side of the tank. Reading the nameplate on the motor gives the real hp at less than 2.

The biggest farce is home vacuum cleaners. Check out the power cord AWG and figuring 400 circular mils per amp as a safe load, no way will that power cord sustain the advertised HP on anything but a quick burst.

California · Aug 26, 2018

Years ago Sears lost a case re unobtainable horsepower ratings. i thought it was compressors but it could have been vacuums.

HF has reduced their compressor ratings. The one I bought that they rated (90 psi), something like '5.8 cfm' is now rated more like '4.8 SCFM'. Same hardware. Still claimed 2.5 hp at 13 amps or less, that's impossible.