what are the best 4.5" cutting discs

[md21722]

for an angle grinder?

or is it normal for cutting an 8x8 inspection hole plus one side of a 20 gallon air tank to require more than one.. using one of the Diablo 40 grit discs from HD.

It's my first time with a 4.5" angle grinder. The tool did the work quite well, didn't seem like I needed "force it" to work.

 

[robert2008]

The key is to let the tool do the work and not put a lot of pressure on it as your cut. You'll wear them out a lot slower. I bought two of the 10-packs from Harbor Freight while working on the floors of my '96 and have been happy with them. At 80 cents a piece you can't go wrong.

http://www.harborfreight.com/pack-of-10-4-1-2-half-inch-cut-off-wheels-for-metal-45430.html

It does help that I have a Harbor Freight two miles from my house.

 

[iluv83vettes]

http://naxja.org/forum/member.php?u=68436

Check with these guys. I bought a grinder, some flap discs, some grinding wheels, some cutoff wheels and a couple of the undercoating remover wheels. They had great service and even better prices. Plus they support .

 

[Hypoid]

The key is to let the tool do the work and not put a lot of pressure on it as your cut. You'll wear them out a lot slower.

And go even slower if it is a new disc. I have been told that new discs have a sort of break-in period for the first couple minutes. I don't know if that is fact or crap, but I get decent life out of the product at my local hardware store.

 

[md21722]

I didn't try to force the tool & read that there was a "break in". It actually cut what it did like butter and wore slowly at first. I couldn't believe I cut as much as I did without any noticeable wear to the wheel. But once it started wearing it wore very, very quickly.

 

[xcm]

Theyre called consumables for a reason. Worry about your technique before worrying about which discs are sliiiightly better than the other. Home depot discs are fine, if not the best priced (if your going thru tons of them)

I watch the dust coming out of the cut, you can see when your being inneficient because theres extra wheel dust, and you can see it.

Its hard to explain, but i use a plunge-advance-plunge technique, where the plunge isnt the full depth of the material being but, and the advance cuts about half way thru, to be finished by the plunge...

Breaking in cut off wheels... thanks for the laugh. Dont abuse them, dont use the everyday ones for metals other than common steels, dont clog them, but break them in? LOL.

 

[Anak]

The Camel wheels are good. So are Norton and Hilti if you can find them. I am not impressed with Harbor Freight abrasives. Tried them once and wrote them off.

 

[ehall]

I use the DeWitt consumables, sold at Lowes. The cutoff wheels work fine unless you twist them (they aren't for polishing)

 

[md21722]

Thanks all. I am new to metal working & not sure how long they should last. I will check out the suggestions provided.

 

[freerider15]

I built the buggy using HF cutting discs.

I tried several others, but at the end of the day...the difference wasn't really much.

HF regularly has the 4.5" wheels on sale for something like $5.99 for the 10 pack.

I picked up half a dozen packs a while ago and still have a bunch around.

They're cut off wheels, not saw blades...aka consumables. Don't think too much into them.

 

[md21722]

Going 90 degrees out, cutting discs create lots of dust to clean up, what does a plasma leave behind? I get that one needs to clean up after the plasma, but I'll probably be getting one for Christmas. And I don't think the standard water separator filter is good enough, is a coalescing filter good enough or should I look to a desiccant filter as well?

 

[Hypoid]

The plasma will generate some slag. If you rent, it would be a good idea to put some sheet metal down in your cutting area.

For moisture, my little Hobart (internal compressor) has nothing, only a particulate filter. So far, so good.

Going 90* out, my local Meyer's hardware sells a 25-pack of cutting discs for less than $20. I have been very happy with the quality.

 

[md21722]

Good points.

My couple of week old Makita seems to have lots its treads on the disc holder/retainer. Not sure where they went but there is no way to hold the disc on anymore. Was tightened with the Makita tool.

Junk from China?

 

[md21722]

This was user error, I had the backing nut without threads in my room hand. Threaded retainer was right by the tool used to remove it. Duh.

 

[rockclimber]

I am going to disagree with everyone here. I think it absolutely matters what quality disc you use.

the HF discs especially and other cheap ones are complete crap.

I have had excellent luck switching to Pearl and Sait discs. I can get 3-4 times the life out of one of those than any HF disc. I go with Pearl discs most often because both the steel supply places near me and the hardware store I frequent stock them in large quantity.
they generally last quite a bit longer than any other disc I have tried. I cut 2 3/4" D ring tabs out of some flat stock with 1 disc.

the other thing to consider is your grinder itself. make sure its at least a 6-7 AMP grinder so it can keep the RPMs up, even when you lean into it. the lower amp grinders will loose speed when they cut and that will wear the disc rather than cut the steel.

also, they are considerably more dangerous, but a 7" grinder will eat through thicker stuff pretty well and cuts things 1/4" and below like its paper.

my .02

 

[md21722]

I've read good things about the Norton's and 3M high end discs as well...

My paddle switch Makita ($79 at Home Depot) is a 7.5A and seems to do OK though I wonder if a 1HP air grinder that sucks 30-35 CFM would be any nicer (it would be less efficient considering air compressor HP needed to run it, but it would be smaller...) and I've heard that the 7" grinders are called ankle grinders.

One thing about air, when you release the trigger it stops, no inertia... no waiting before you put it down.

Plus here in Colorado the air compressors help heat the garage in the winter.

 

[Hypoid]

I am going to disagree with everyone here. I think it absolutely matters what quality disc you use.

the HF discs especially and other cheap ones are complete crap.

I have had excellent luck switching to Pearl and Sait discs. I can get 3-4 times the life out of one of those than any HF disc. I go with Pearl discs most often because both the steel supply places near me and the hardware store I frequent stock them in large quantity....

Thanks for the recommendation! I never heard of SAIT before: http://www.unitedabrasives.com/Docs/Catalog/UA2014Catalog-99002-14.pdf

The intro, starting on page 6, is a good read!

the other thing to consider is your grinder itself. make sure its at least a 6-7 AMP grinder so it can keep the RPMs up, even when you lean into it. the lower amp grinders will loose speed when they cut and that will wear the disc rather than cut the steel.

Interesting, I never heard this before. If this holds true, the linear velocity of the circumference of any rated cutting disc, should follow the same principle.

my .02

Then again, I'm the "Tribal knowledge" S.O.B who still breaks in his cutting/grinding wheels on the angle grinder, chop saw, bench grinder...

P.S. I tried the HF cutting wheels in 2003. All other things being the same, they did not rate a second purchase.

 

[md21722]

P.S. I tried the HF cutting wheels in 2003. All other things being the same, they did not rate a second purchase.

Another satisfied customer!

 

[xcm]

There is absolutely zero need to use the wrench to tighten grinding discs to a grinder.... grab the wheel, turn it clockwise with your hand, and goto town... dismounting is the exact reverse of mounting....


I take that back, the ONLY time to use the wrench, is after some noob tightened a wheel on super tight for no reason. This is a total pet peeve of mine...

 

[md21722]

I got my hands on a 3M 28405 -- 1HP 4.5" 12,000 RPM industrial angle grinder. All I can say is wow. Cuts butter smooth with little to no vibration compared to the electric Makita and I wasn't able to stall it. It does use a staggering amount of air. Catalog says 37 CFM. The air inlet is 3/8" NPT similar to what you'd see in 3/4" or 1" impact wrenches....

Any ideas why the Makita has a lot more vibration? Is it common with electric angle grinders? specific to the Makita? or are the industrial tools just that much better?