This specification establishes the manufacture of and requirements for two types and two grades of electrical insulating tape consisting of a polytetrafluoroethylene (PTFE) film coated on one side with a pressure-sensitive adhesive. Type I is standard backing, while Type II is bondable backing tape. Grades are designate based on backing thickness. Besides standard lengths, widths, and thicknesses, tapes shall also conform to other requirements such as breaking strength, elongation, adhesion to steel and backing, dielectric breakdown, and high-humidity insulation resistance.