Общий каталог PRECITOOL - страница 856

Tool grinding wheels Product information The choice of an abrasive depends on the type of workpiece to be ground and its properties as well as the operating conditions. For the different application areas we offer abrasive products made from the following artificial grinding media: Standard corundum For machining iron and low-grade steel. Special fused alumina for machining alloyed steels, tool steel and high-speedsteel (HSS) and steels sensitive to heat. Silicon carbide For machining carbides, short-chipping materials like aluminium, copper, plastic, glass, china, ceramics etc. Grit grade The degree of fineness of a surface to be ground depends quintessentially on the size of the abrasive grain used. Superior demands to the surface will be met by the choice of finer granulation, coupled with the acceptance of a reduced cutting per- formance. NK = Standard corundum EKW = High grade corundum, white, high tenacity very hard and brittle EKD = special fused alumina, rose very SiCg = SiC, green KA or Z = zircon corundum very high hard, higher grain tenacity han extremely hard and brittle mechanical tenacity EKW Hardness of the grinding disk Speaking of hardness with regard to a grinding disk is not about referring to mineralogical hardness of the embedded grain, but in fact it is understood as resistance or force required to break one or more abrasive grains out of the bonding union of a grinding disk. As a broad rule of thumb: The grinding wheel hardness should be inversely proportional to the hardness of the material to be machined. For hardened steels a softer hardness is chosen than for uncured ones. According to DIN 69100, the hardness of grinding disks is denoted by the following letters: very soft E F G soft H I J K medium L M N O hard P Q R S very hard T U V W extremely hard X Y Z www.precitool.de 46/851