Flap Disc Classification Guide

Form: Flat (T27) VS Conical (T29) 

Generally speaking, flap discs can be classified into two groups from the perspective of form, namely flat and conical. The flat is also called Type 27 and the conical refers to Type 29. The polishing surface of flat flap disc is smooth and mainly used to polish surface and external angles. The ideal working angle arranges from 0° to 15°. It is the best choice for blending and smooth finishing. The stock removal and surface finishing are finished in one process, which reduces working process. While, conical flap discs have angled flaps which make them have better surface contact and better stock removal capacities. The ideal working angle of conical flap discs are between 15° to 25°. Conical flap discs are mainly applied into the grinding of outline and edges. When speed and stock removal are primary considerations, conical flap discs are the best choices. 

Grains Type: Ceramic Alumina VS Zirconia Alumina VS Aluminum Oxide

According to the grains types, flap discs can be grouped into three, including Ceramic Alumina, Zirconia Alumina and Aluminum Oxide. Ceramic Alumina has numerous crystals, and has good self-sharpening ability. In the process, ceramic alumina could keep consistent sharp edge, and because of its good performance of dissipates heat, ceramic alumina flap disc has a long life. The ceramic alumina flap discs are mainly used in cutting stainless, aluminum and other hard metal. Zirconia Alumina has multi-crystal structures, fast cut rate, good self-sharpening and stands up to heavy pressure and high temperatures. Because of its features, Zirconia Alumina flap disc is often used in high rate of stock removal. While, aluminum oxide consists of single crystal, so the cut rate declines at start of grinding, and the grains are hard to fracture. As a result, aluminum oxide flap disc is often used in general metalworking application.