A smooth, well finished metallic surface may be required for either aesthetic or functional reasons. Without a good start, one cannot expect to achieve a good finish and selecting the appropriate product will require some insight into the required end result, be it painted, polished or raw material look.
Considering that the go-to disc for stock removal has always been the rigid abrasive grinding disc, with the use of flap discs becoming more and more popular, one needs to first understand what an abrasive flap disc is. Unlike a traditional resin fiber disc, the abrasive flap disc is a single unit that contains its own backer. Abrasive flaps are arranged radially and in an overlapping format on the face of the backer and glued into place. Flap discs come in various shapes, sizes and formats with distinctly different shapes.
Shape or Type 27, also known as flat, is best used for blending, smoothing or finishing applications and suited more to flat surfaces being ideal for deburring and edge grinding applications. Shape or Type 29, commonly referred to as conical works best for aggressive stock removal, where speed and cutting ability is required. The Type 29 provides a greater contact area with the angle of the disc for improved stock removal on flat surfaces.
Flap discs are manufactured from a range of different grains, each with its own properties suited to specific applications.
Alumina Oxide, red-brown in color, is the most cost-effective grain and usually reserved for light industrial or general-purpose jobs on soft metals and woods.
A more premium, high-tech grain, Zirconia, is blue-green in color and this grain self-sharpens as it wears away during application. Designed to provide high stock removal with fast cutting, this grain offers reduced heat generation with a cooler grind in the material.
