Lasts up to twice as long as a Bosch standard metal disc. We developed the PRO Metal for metalworkers who need a reliable and durable grinding disc for metal. The long-lasting PRO Metal bonded grinding disc is equipped with high-quality aluminum oxide grains to efficiently grind metal and steel. We combined the grains with functional fillers and embedded them in a phenolic resin matrix for stability, heat resistance, and reliable grinding performance. A precision-engineered fiberglass fabric reinforces the disc and provides additional safety. It is free of iron, so you don't have to worry about rust on your workpiece when cutting stainless steel. With a 16 mm bore diameter for standard angle grinders with a clamping nut.