The advances made in understanding the mechanisms of molten materials from micro- and nanoscales have led to innovations in materials processing that are creating new products to revitalize established industries. One such industry is the abrasive materials sector that is becoming increasingly dominant because ultra-precision machining of surfaces requires harder and tougher materials that can withstand the perils of material removal due to the size effect. Improved abrasive materials in the form of grits, or collections of grits need to resist scuffing (fracture due to instantaneously high temperatures) and pitting (fracture due to high contact stresses) that can lead to collapse of the surface of the grinding wheel by the loss of collections of grits bonded together. This chapter reviews and discusses the manufacturing of fused aluminum oxide (α-Al2O3 or α-alumina) in its near purest form known as white fused alumina (WFA) and monocrystalline alumina (MA) manufactured using the Bayer process and Haglund process and by mechanical stirring of solidifying melts using rotating carbon rods immersed in molten alumina. The chapter concludes by comparing the cutting performance of abrasive grits using single-grit fly-cutting technique.