Benchmark Abrasives 4 1/2 Inch Sanding Discs Ceramic Resin Fiber Grinding Disc for Grinding, Stripping on Wood, Fiberglass, Metal, 7/8" Arbor Angle Grinder Sanding Disc, 25 Pack - 24 Grit

The discs remove mild steel at lease twice as fast as a normal disc and last a lot longer.

Works great cuts fast very sharp

It says it works on metal. This product is not for smoothing welded joints. One disc only handled four 2" welds before having to replace it. The price might be low, but when you use 4 times as many as a higher priced better quality product, the math doesn't work out. It probably is fine for softer materials.

Hubbt bought these. Love the value for money!

I will be using these Benchmark 4-1/2” 60 grit fiber discs on my Craftsman angle grinder that has 7/8” arbor. Per the recommendation by Benchmark I mounted the disc onto 4-1/2” rubber backing pad. My backing pad is an old Craftsman part number 927020. On Amazon I’m seeing mostly rubber backing pads for 5/8” arbor. But I did find one that accepts 7/8” arbor. Not surprisingly it is by Benchmark:Benchmark Abrasives 4.5" Air-Cooled Poly Pad Resin Fiber Disc High-Quality Backing Pad.I tried out one of the Benchmark Ceramic Resin Fiber Discs by grinding a bevel along the edge of a piece of mild steel and it worked well. After grinding I examined the disc and it showed very little sign of wear, i.e. no areas where the grit had been removed. Based upon my short term use of this product I’ll give it a 5 star rating.

I’m a woodworker and DIYer and use these sanding disks to hog out wood for the seat bottoms on the stools and chairs that I make. They hog out wood very quickly, so I have to be careful when getting to my final depths and switching to finer sandpaper. They also last a while since I’m using them on wood and not steel (so far). I also have cutting discs for my angle grinder, but somehow I feel a little safer with a sandpaper disc spinning around vice steel blades.I measured the outside diameter with calipers at 4.522” and the discs fit my backing pad without any issues. Remember these disks are for an angle grinder and you’ll also need a backing pad and nut. These discs don’t have any slots radiating from the center arbor hole like some of my other discs, but I really haven’t noticed a difference in performance yet.Overall not a bad deal since each sanding disc is just a little more than a $1.

I use alot of sanding discs and these do not last like other ceramic discs I have used I will not be buying this brand again

These abrasive disks will get the job done! The question being how many you'll need to do so is the "million dollar question". A pack of twenty five, if chosen in the right grit, can make a job much quicker. However one could argue that a "mixed pack" would be of more use.