The results of development of the technology for manufacturing samples of insulators made of alumina ceramic with an aluminum oxide content of up to 95% are presented. The maximum tensile strength of the produced insulators has been investigated. The structures of the chip of the ceramic insulator surface have been obtained. It is shown that a change in the aluminum oxide content by 8-10% leads to an increase in the strength properties of the product by 1.5 times. The developed technology can be used to produce high-strength dielectric products, for example, antenna rod insulators, applied in the field of electrical engineering, radio engineering and other industries.