What's your favourite cutoff disc?

I currently have as much money spent on 4" cutoff discs as I've spent on steel to fab my Challenge car. I buy them a dozen at a time. The bulk of them has been Norton or DeWalt brands, with some Menards store brand thrown in. None of them lasts very long. What brand do you gravitate to and is it for any particular reason aside from "that's what my local store sells" ?  A lot of what I've been using them for is slicing sheet metal, hacking brackets off an axle and some contouring tube ends for cage fitment. I have not sprung the funds for one of those "miracle" diamond dusted cutoff wheels that are claimed to last so much longer. Anyone have experience with one of those?

No input on any discs, but I'm curious why you're using them on sheet metal.  I usually go to shears or maybe a saw for that.

I personally don't like the diamond cut off wheels. They do last a long time (as long as you don't overheat them and weaken the brazing on the diamonds) but they are loud and rough. 

Most of the ones you'll find at local stores are probably the lowest price point option and likely aluminum oxide grain. If you can find one with a zirconia or ceramic grain they will have much better performance. There are a lot of brands out there so if you are buying one of their more premium products you should have good luck. Try to stick with ones that are made in USA or Germany. Rex-Cut, Pferd, Norton, 3M, Weldcote, etc all have good products. 

Funny enough I find the best ones at Canadian Tire. Just bought a pack of 20 for $9.99 Cnd and am surprised how long they last.

I buy the harbor freight ones... and I still have all my fingers. 

I've bought the abrasive cut-offs by the box from the local welding store, last batch was Norton (or an offshoot of them), and they have done much better than prior cheap HF wheels.  I did buy a mixed kit of cutoff wheels and flap discs from Benchmark Abrasives and have been really happy with those. The cutoffs work well and the flap discs seem to last a decent amount of time.  You can usually find discount codes floating around for them too.

I have to second the prior comment on the diamond cutoff wheels.  They work, but are LOUD, and very chattery. I wear ear plugs inside on ear muffs and they still scream. Great way to make friends with the neighbors!! They are okay for thicker wall tubing, not so much for thin material.  

I buy cheap ones at Princess Auto. (Western Canadian Harbour Freight, kinda)  

For long life, don't cut sheet metal by burying the blade in the metal, cut the surface.

For longer life, but a five, or even a seven inch blade, because they will eventually wear down to a four inch blade...  I have a seven inch grinder that will cut a lot of material before I get it down to four inches.

The ones that explode in my face and give me shrapnel, despite wearing proper PPE. 

Streetwiseguy said:

I buy cheap ones at Princess Auto. (Western Canadian Harbour Freight, kinda)  

For long life, don't cut sheet metal by burying the blade in the metal, cut the surface.

For longer life, but a five, or even a seven inch blade, because they will eventually wear down to a four inch blade...  I have a seven inch grinder that will cut a lot of material before I get it down to four inches.

To add to Streetwiseguy's comments, there are some very thin blades out there that work really well for sheet metal. Thinner means less material removed and less heat in the part you are cutting. The typical box store stuff only gets down to 0.063" or so. The ones we use to build Cup cars are generally 0.040" thick. They will break easily if you get them bound up, but the go thru sheet metal much faster and with less heat. To re-state the comment above, use the longest bit of blade you can to cut with. If you use the blade as close to the center of the exposed edge, it will wear out very fast.

I think Dusterbd was keeping the used cutoff wheels from the AMC build and photographed the pile toward the end of that build. We did use the diamond edged blades toward the end and found them to work great on steel, not so much on aluminum. Also, if they hang in the cut they grab really hard and try to pull the grinder out of your hands instead of breaking. Side note, I have used a diamond balde to cut up windshields, but the finish is not great.

I've been really happy with the junk from HF.

I've used the diamond tip type(diablo?) and although it lasts longer I've not been super happy with the cut quality, cut speed or the noise.

I have the thinnest Milwaukee ones from Home Depot. Still barely have used anything from the first one.

Avanti when HD has the 20 packs for $25.  They cut nice and last a decent amount and don't make me get stitches like the metal diamond blade did

Mr_Asa said:

No input on any discs, but I'm curious why you're using them on sheet metal.  I usually go to shears or maybe a saw for that.

I use my reciprocating saw, but it can't get close enough when I'm working the inside of the rocker panels and along the flange of the firewall. 

Lots of different views and brands. I'll have to go see what the local welding store carries and what they cost. I do have multiple choice for different cutting devices, a saw, a power shear from the hammer store that works surprisingly well, tin snips, a chop saw and several HF angle grinders with various flappy discs or cutting wheels. I even bought the HF tube notcher to make things easier. The cutting discs are the biggest expense though (4 or 5 dozen used so far), that's why I asked.

In reply to Streetwiseguy :

I watch a lot of those car fab shows on Motor Trend TV and they all use a big disc with no guard. I'm surprised that they still seem to have all their fingers.

In reply to NOHOME :

I'd go to the Canadian Tire storein Windsor at that price, but the hotel bill for the 14 days of quaratine would suck up any savings......

I've bought the Canadian Tire discs in packs of 20 and packs of 50 and I pretty much clean them out between me and work.

Apparently a disc rated for -Stainless- will last longer and leave much less dust.  I will try them after I've gone through my HUGE stack of CDN Tire discs.

DeadSkunk (Warren) said:

In reply to Streetwiseguy :

I watch a lot of those car fab shows on Motor Trend TV and they all use a big disc with no guard. I'm surprised that they still seem to have all their fingers.

I have no guard.  I am very aware of the spinny stuff, and that is the number one focus.  Always be aware of the spinny stuff.

I use grinding discs as cutoff discs more frequently than I use exploding death wheels. There are better tools for long cuts (plasma, saw, shears), and it's often not worth changing the disc for short ones. At least when I can afford 1/4" kerf.

I've used HF a lot and they're ok. The DeWalt ones are a little better, mostly enough to be worth the price delta. Tried one of the Diablo ones. Wasn't impressed. 

I'm happy enough with the Diablo stuff myself.

A lot issues probably stem from usage.  Technically, cutoff wheels have a VERY narrow use case range.  Anything outside of that and their life basically goes to crap.

For some fun reading and some hilariously manly photo shoots, read the Norton Abrasives catalogue:

https://www.nortonabrasives.com/sga-common/files/document/catalog-nortonweldingmetalfab-7364-bookmarked_2.pdf

My local welding shop sells SAIT and I've had good luck with them. I've even dropped a grinder and the disc never shattered, just chipped.

These, bought by the box. Black Hawk Metal and Stainless Steel Cut Off Wheels

I also use their flap wheels. 

Benckmark Abrasives https://benchmarkabrasives.com/

Hands down the best cutting/grinding products I've ever used. Cut off wheels last noticeably longer than I expect them to and the flap discs just keep going and going. I toss those when there's almost nothing left. 

I tried them on a whim from Amazon since the store ones are so damn expensive. I did 1 each of 10 pack of 40 grit/80 grit flapper discs and a 50 pack of cut off wheels. That got me through the all the frame off/chassis modifications and roll cage on the cutlass, and a full roll cage worth on another car plus lots of little odd jobs here and there. I just reordered more flapper discs (it have been almost a full year) and still have half the cutoff wheels left. Extremely happy with them.

I would also vouch for Benchmark. I had a Facebook ad for a coupon for a "free" pack of flap wheels from Benchmark Abrasives (just pay $19.99 shipping and handling). I'm very very impressed with the flap wheels, it's been nearly two years and I still haven't used up the whole assortment. If Benchmark also offers cutoff wheels, I bet they're quite good.