3M Cubitron II Fibre Disc 982C, Pack of 25, 4-1/2 in, TN Quick Change, 36+ Grit Precision-Shaped Grain Abrasive Discs, for Heavy Grinding, Deburring, Beveling, Finishing, and Weld Removal

You're not going to believe me until you try them yourselves, nobody ever does. I use these as a shipyard Fitter/Welder, I've used them building rock crusher 4X4 bumpers and I've used them making electrical boxes. These are more aggressive than a hard grinding disk on a 9" when it comes to material removal & leave a paintable smooth finish for heavy industrial applications. They take off about as much steel (just much faster) than a hard disk before they're worn out, and they're safer because they can't explode. These are ceramic grinding disks, they're not just sanding disks. These save tons of time finishing and deliver much higher quality than hard disks. You really do have to try them to believe it though because they do LOOK like sanding disks. Their only downfall is that the edges, if you're a welder. They're not for fixing lumpy fillets because if only using the edge you'll wear it out quickly, and waste money being as these are rather pricy. That, and if you use them on welds that haven't cooled for a few minuets you'll get a much shorter life out of them due to the heat. So if you're primarily a welder, I'd stick to hard disks. If you're a fitter and you need to remove a lot of metal real quick & leave a high quality finish while coping or blending, these will save you a ton of time and money. Good luck, and don't forget to buy a backing pad if you try them.

These are just about indestructible. The grind and blend metal so fast and cleans and they last forever. Well worth the money

Cuts steel/ welds great

Got the 7" 36 grit discs that have the little metal ring and tabs. Trying to find the proper backing pad and nut has been impossible to figure out. It says in the description that it uses the 3m GL (grit lock) attachment system, but I can't find one that is compatible with 7" pads, and I can't even figure out how it works or what it looks like. Not a single video on YouTube, no links or parts numbers. total pain in the butt! Common y'all!

Simply the fastest grind I’ve seen for removing welds in sheet metal to make flat. Lasts much longer than I thought. The metal shards/dust really flies so wear a respirator mask and goggles.Now looking for the equivalent of this for use in tighter spots as this is good for flat and open areas but the big 4.5” grinder won’t fit in tight spots or work well on uneven areas - there is no grinding edge like on a fixed hard grind wheel, so can't turn on edge to get on a narrow area.For flat open spots you’d think it was wood not steel as it goes away so fast.

Love cubitrons…. They grind metal like nothing else… this seller “contractor source” sucks tho.. they keep sending me the wrong ones.. I’m ordering the quick change version that have the metal screw nut in the center but they keep sending the non quick change version that requires an extra piece in addition to the backing pad…. Too many extra parts to keep track of in the field and that if nut gets dropped and lost the pads are useless…. The quick change version can be screwed on to a 1/8 grinding disc, no extra parts needed, nothing to lose..

I've been in the business for forty years and these have to be the best discs I've ever used. I use them for weld blending. They are fast and long lasting. I would highly recommend.

It cleans off light millscale then polishes after it has been wore out. Pain to change out. Gets so tight on the backing pad I have to use channel locks to take off.