The insulators are made by bonding a ceramic piece with upper and lower metal attachments using an adhesive. The contact areas between the ceramic piece and metal attachments are padded with elastic washers. The bonding areas of the ceramic pieces feature structures such as sandblasting, knurling, and grooving for mechanical strength, anti-loosening, and anti-twisting. The ceramic surface is evenly glazed white, and the metal attachments are coated with gray magnetic paint. The main structures of the ceramic pieces include hollow partition (penetrable) and solid (non-penetrable) structures. The combined bonded pillar insulators are generally solid and non-penetrable. The latter structure reduces maintenance and testing work compared to the former. The ceramic pieces come in two shapes: multi-angled or less-angled. The multi-angled shape increases the surface distance and has better electrical properties than the less-angled shape. All products except the gradually phased-out external bonded pillar insulators are multi-angled. The internal bonding structure, due to the metal attachments being glued into the ceramic holes, increases the insulation distance and improves electrical performance, while also reducing the space required for installation. However, since internal bonding is不利于 enhancing mechanical strength, insulators requiring high mechanical strength should use combined bonding (i.e., the upper attachments use internal bonding, and the lower attachments use external bonding).