Listed by OD or A dimension, Screw Insulators are precision molded of nylon 6/6 - a highly crystalline, light-weight, high melting thermoplastic resin. The mechanical advantages include toughness; good thermal properties; abraision, friction, and chemical resistance. Parts are natural but can be dyed black or various colors on request! Specify color at checkout! Max. tensile strength: 12,000 PSI., resistance to heat: 270-300 deg F.