All top surfaces are .080" thick with integral stiffener ribs and have 1 1/2" profile edge. Tops are constructed of individual aluminum boards bolted together and have longitudinal seams. End caps are heavy gauge and have high impact cast corner inserts which will absorb abuse from frequent setup and take down. Table tops will not crack or warp after extended usage or exposure to heat, moisture or sunlight. Tables have permanent scratch-proof stacking bumpers attached to the legs to prevent damage when stacking. Table corners will withstand a drop squarely on edges/corners from a height of 24" at any temperature without splitting apart, cracking, or creating sharp corners. Tables will not emit toxic fumes, gases or smoke in high temperatures related to a fire (passes California Fire Code 133). Tops will not conduct electrical current.