By sharpening with a pendulum motion you work a little less fast, but your disc really lasts much longer and that saves you time to change! You also bring in less heat, which results in less distortion and discoloration. Learn more tips about sanding and grinding metal in the METAC. This is our own training centre in which we teach you a piece of theory in one day, which we test extensively in practice. Here you can read more about METAC:
Read our white paper on metal cutting and what factors affect the life of your disk.