Abstract: A process for the production of a ceramic polycrystalline abrasive by the sol/gel method is characterized in that an intermediate containing aluminium hydroxide is mixed, dried, calcined and sintered with a further intermediate having different degradation properties. The further intermediate is expediently formed from a calcined aluminium hydroxide.

Abstract: The back finish of a flexible grinding tool, especially a grinding belt, tains an ingredient which is composed predominantly of plate-like mineral particles, preferably micaceous iron ore. It gives the belt a higher rigidity and better sliding properties on its back.

Abstract: Abrasive belt with an abrasive-grain layer on a base containing a textile terial, and with a joint extending transversely to its longitudinal direction. The latter contains a joining strip in a rebate on the side of the base facing away from the abrasive-grain layer. A set of parallel threads of the textile material extends transversely to the joint. To increase the quality of the joint, the textile material used is one in which the set of parallel threads forms a non-interwoven layer. This thread layer is arranged on the side of the textile material facing the abrasive-grain layer. This layer is held together by a further layer arranged on its side facing away from the abrasive-grain layer. Since the rebate is located in this further layer, the threads responsible for transmitting the longitudinal tensile forces and extending transversely to the joint remain unaffected.