The insulators are made by bonding porcelain components with upper and lower metal fittings using adhesive. The contact areas between the porcelain components and metal fittings are padded with elastic washers. The bonding sections of the porcelain components feature structures such as sandblasting, knurling, and grooving, providing mechanical strength, anti-loosening, and anti-twisting properties. The porcelain surfaces are evenly coated with white glaze, and the metal fittings are painted with gray magnetic paint. The main structures of the porcelain components include hollow partition (piercing-through type) and solid (non-piercing type) structures. The combined bonded pillar insulators are generally of the solid non-piercing type, which reduces maintenance and testing work compared to the previous type. The porcelain components can have either multi-angled or less-angled shapes, with the multi-angled shapes increasing the surface distance and having better electrical properties. All products except the external bonded pillar insulators to be phased out are of multi-angled shapes. The internal bonding structure, where the metal fittings are glued into the porcelain holes, increases the insulation distance and improves electrical performance, while also reducing the space required for installation. However, due to the negative impact on mechanical strength, insulators with higher mechanical strength requirements should use combined bonding (i.e., the upper fittings use internal bonding, and the lower fittings use external bonding).