Porcelain insulators have prodigious importance in electricity transmission and distribution network because of their high dielectric constant, electrical resistivity, and mechanical strength and these properties are closely connected to the microstructural details of the insulator. Three different porcelain insulators (Sample A, B and C) were reported in the present work. X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), three point bending test and density and pore analysis were carried out to investigate the structural and mechanical properties of various insulators. The analysis confirmed that the porcelain insulators are made of industrial alumina, quartz, clay, and feldspar having amorphous as well as crystalline phase in the body. The porosity, density, and bending strength were also calculated and a correlation was developed between mechanical strength of the insulator and various physio-chemical and microstructural properties. Sample A showed the highest value of bending strength i.e. 207.20 MPa and sample C the lowest value of 112.18 MPa while sample B demonstrated the intermediate value of 170.98 MPa. To formulate high strength porcelain insulators, it was concluded that the amount of amorphous phase, dispersed corundum, and mullite content are key factors to control the mechanical strength of porcelain insulators.