On Thu, 5 Oct 2017 15:32:49 -0700 (PDT), "
wrote:

On Friday, July 14, 2017 at 2:37:00 PM UTC-4, wrote:
I compared a Pferd 40 grit flap disc made for stainless steel to a
Cubitron II flap disc made by 3M. The Cubitron cuts at least 3 times
faster than the Pferd disc as well as wearing better than the Pferd
disc. I am truly impressed with the Cubitron II flap discs and will be
buying them now instead of the Pferd.
Eric

I ordered a cubitron ii flap disc , a 4 1/2 by .25 and a 4 1/2 by o.45 cutoff disk. And today put them to good use. At the local scrap yard I picked up four pieces of 3 by 4 square tubing that had a 3/4 inch thick plate welded on one end. The plate was welded on two sides. I used the .25 thick disc to remove most of the weld and then used the o.45 cutoff to get most of the remaining weld. A BFH hammer broke the remaining weld.

The cubitron disks worked very well. Cut fast and did not require a lot of pressure. Much easier to control when you do not have to apply much pressure.

The medium priced 4 1/2 inch Harbor Freight angle grinders are pretty good, but the disks from HF can be worthless.

Dan
I'm glad you have had the same experience I have had with the Cubitron
flap disc. They really are a great cost reducer compared to cheap
discs and even some expensive ones. Sorta like how solid carbide
endmills today are rwally a better deal than HSS for most stuff. They
last so long, cut so much faster, and if you have the equipment to
take advantage them carbide endmills are way better than HSS.
Eric