| Halar | A trade name of Ausimont USA for their copolymer or ethylene and chlorotrifluoroethylene. Abbreviation ECTFE |
| Halogen | Any of the five elements: Fluorine, chlorine, bromine, iodine and astatine. These elements may be combined with insulation compounds to enhance flame retardancy. |
| Hard Drawn Copper Wire | Copper wire that has not been annealed after drawing |
| Harness | An arrangement of wires and cables, usually with many breakouts, which have been tied together or pulled into a rubber or plastic sheath, used to interconnect an electric circuit |
| Hash Mark Stripe | A noncontinuous helical strip applied to a conductor for identification |
| Heat Distortion | Distortion or flow of a material configuration due to application of heat |
| Heat Endurance | The time of heat aging that a material can withstand before failing a specific physical or electrical test |
| Heat Resistance | Ability of a substance to maintain physical and chemical identity and electrical integrity under specified temperature conditions |
| Heat seal | A method for sealing by thermal fusion |
| Heat Shock | A test to determine stability of a material by sudden exposure to a high temperature for a short period of time |
| Helical Stripe | A continuous, colored, spiral stripe applied to a conductor for circuit identification |
| Henry | Unit of inductance such that the induced voltage in volts is numerically equal to the rate of change in current in amperes per second |
| Hermetically Sealed | A gastight enclosure that has been completely sealed by fusion or other comparable means |
| Hertz(Hz) | A term replacing cycles-per-second as a unit of frequency |
| High Voltage | Generally, wire or cable with an operating voltage of over 35,000 volts |
| Hi-pot | A test designed to determine the electrical integrity of an insulation |
| HIPPI (High Performance Parallel Interface) | An ANSI standard which defines the mechanical, electrical, and signal protocol requirements for a simplex, high performance, point to point interface between data processing equipment |
| Hook-up Wire | A single insulated conductor used for low-current, low voltage (usually under 600 volts) applications within enclosed electronic equipment |
| Hygroscopic | Capable of absorbing and retaining moisture |
| Hypalon | DuPont's trade name for their chlorosulfonated polyethylene, an ozone resistant synthetic rubber |
| Hz | An abbreviation or hertz |
