Let me start by saying these flap discs are a STEAL for the price. I've burned through countless grinding wheels on my DeWalt angle grinder, and this 40-pack assortment is my new go-to for quick jobs.

The fiberglass backing is a nice surprise - way more durable than the flimsy plastic ones I've used before. When grinding down some rusty trailer hitch parts, they absorbed vibrations like a champ without that annoying 'bouncing' effect cheaper discs have.

That Type 29 bevel? Game changer. I could actually get into the tight corners of some wrought iron fencing I was restoring. The 40-grit discs eat through rust like popcorn, while the 120-grit leaves a shockingly smooth finish on aluminum patio furniture.

Now the not-so-great: The labeling situation is annoying AF. I had to Sharpie grit numbers on each disc after opening packages - dropped one in my workshop and spent 10 minutes squinting at it like an archaeologist. Also, they do shed grit aggressively at first (wear goggles!).

Pro tip: Store opened packs in ziplock bags with grit labels. These aren't 'buy-it-for-life' quality, but at less than $1 per disc? When one wears out, I just grab another without crying over my wallet.

Final verdict: Perfect for DIYers and pros who burn through discs regularly. Would I use these for aerospace-grade metal finishing? No. For 95% of garage and jobsite tasks? Absolutely yes.