difference between 4 & 4.5" angle grinders

[eljefino]

Been catalog shopping and like I always wondered, what's the difference? Maybe the arbor hole in the middle is also different? My grinders have a flip-overable washer thing that seems somewhat universal when it comes to fitting wheels.

Anyone have any issues like the spark guard is too small to fit a 4.5 wheel on a 4 inch grinder?

Just wondering about the seperate evolution these things took. Maybe the 4" was an air tool size at one time?

 

[IndyIan]

$50?

I always see 4.5" and 5" up here. I know my cheapo 4.5" won't fit a 5" sanding disk(bought the wrong size). The bigger disk diameters will have slower max rpm ratings, so running a bigger disk on a smaller grinder might be a bad idea.

 

[willix]

Isn't 4.5" the small grinder standard? Even in Canada? If it adapts to the arbor correct 4 to 5" should work. Sometimes the guard needs to come off to do a particular job. The goggles remain.

 

[tom slick]

4" will not have the same selection of discs that 4.5 will. 4.5 usually have more power also.

The arbor size is different between the two. 4" will have a 5/8" arbor, everything bigger will be 7/8".

5" grinders are usually a larger machine with a different handle and more power than 4.5.

 

[kkreit01]

1/2" -- can't believe someone didn't beat me to it...

 

[ksJoe]

The difference is, with 4" there's a chance you'll have to take the guard off to use the disks you buy on sale. But no worries, the guards come off easily.

 

[IndyIan]

Originally Posted By: ksJoe
The difference is, with 4" there's a chance you'll have to take the guard off to use the disks you buy on sale. But no worries, the guards come off easily.

No worries until you need the guard... If I did my math right my 4.5" 11000 rpm angle grinder has the outside edge moving at around 140 mph. If you are using horror freight discs then I'd keep the guard.

 

[Jeff3126]

I bought a 4" angle grinder from harbor freight. It has a 7/8" arbor and its hard to find anything but basic discs for it. Should have got the 4.5", or not have gotten the HF POS in the first place.

 

[eljefino]

Well I got a 4 incher from northern tool. The 4.5 discs have 26% more area FWIW. The arbor is different/smaller. I have a couple broken 4.5" with the same exact body so if I get really mad I'm sure I can make a mongrel. One I worked so hard the motor overheated and acrid smoke came pouring out the vents presumably from the windings burning up.

Will look at the 4" cutting disc availability first.

The guards come right off and I'm sure they interchange. No amount of interchanging removable parts gets me 4.5", by intentional design I'm sure, and all right with me, really.

PS just figured out the button locks the gears while one is unscrewing the lockdown ring to change discs. I'd been jamming a screwdriver in the motor cooling fins all these years.

 

[IndyIan]

Originally Posted By: eljefino

PS just figured out the button locks the gears while one is unscrewing the lockdown ring to change discs. I'd been jamming a screwdriver in the motor cooling fins all these years.

Don't you read the manual!?

You guys really need Canadian Tire down there, the rule is you only buy tools on sale, and you get a 3 or 5 year instore warranty on thier mastercraft brand. The mastercraft brand is all made in china junk but built sort of better than the chinese mystery brands IMHO. Anyways my grinder was $20 (on sale of course, the regular price is a ripoff at $60) and when its time for a new one you dig out the reciept and go get one. Or if you decide not to get a khrappy one again you can get an instore credit instead.
Khrappy tire angle grinder