Review on 🛠️ Benchmark Abrasives 4.5-inch x 7/8-inch Premium Zirconia Flap Disc Grinding Wheel 40 Grit Type 29 - Pack of 10 by Mike Donathan

I don't know why anyone would use hard rocks anymore. The Petal Discs are MUCH faster and the cost increase over Hard Rock is negligible. Store-bought materials are relatively cheap, TIME is precious, anything that improves productivity is at least worth a look. I always have at least one grinder with one of these petal discs in it. This is a great product that comes at a fantastic price. Lots of petals and hard abrasive, they last a long time and wear well without excessive vibration. 40 grit is an excellent general purpose fabrication flap disc. Good for removing mill scale, edge chamfering, deburring and some stock removal. It's too aggressive for buffing or anything like that. I don't do anything, it's nice, just functional. I will definitely order again.