How do you make an already great student chair better? Add mobility! Hard plastic school furniture is a great choice when you need items that can stand up to the toughest environments. With a 5/8” thick solid molded thermo-set plastic seat and a steel frame, the 510 Series Chairs by USA Capitol are solidly constructed and guaranteed to last. 5/8" thick posture contoured solid molded thermoset plastic with smooth molded edges and permanent color throughout thickness.