Heat shrink tubing is a shrinkable Nylon or Polyolefin tube used to insulate wires, providing abrasion resistance and environmental protection for stranded and solid wire conductors, connections, joints and terminals in electrical work. It can also be used to repair the insulation on wires or to bundle them together, to protect wires or small parts and to create cable entry seals, offering environmental sealing protection. Heat shrink tubing shrinks radially when heated, to between one-half and one-sixth of its diameter.
Heat shrink tubing is manufactured in a multitude of varieties and chemical makeups with the exact composition of each type being dependent on the intended application. From general use thin-wall tubing to rigid, heavy-wall tubing with varients available with adhesive inside, each type has precise design and chemical additives that make it suitable for meeting any of a wide variety of environmental demands. Heat shrink tubing is rated by its expansion ratio, a comparison of the differences in expansion and recovery rate.