Phosphor Bronze:

This strong and relatively hard alloy is used to fabricate metal parts and springs. Phosphor bronze is resistant to corrosion.


A quantum of electromagnetic radiation, a unit of light. Light can be viewed as a series of photons.

Physical Contact (Fiber Optic):

Abbreviated as PC, this is a design feature of fiber optic connectors, where the mating contacts' faces are in contact and under pressure provided by springs, resulting in lower loss.


A numerical prefix denoting one-millionth of one-millionth (10-12).

Pin Contact:

A male-type contact, usually designed to mate with a socket or female contact. It is normally connected to the "dead" side of a circuit.


Small holes visible on the surface of soldered joints, which generally indicate the presence of a larger void within the joint. Typically caused by the generation of gas during solidification due to presence of salts and water. Sometimes called blowholes.

Plastic Clad Silica (Fiber Optic):

A fiber structure where the cladding around the core is a soft plastic, abbreviated PCS.

Plastic Fiber:

An optical fiber made of plastic alone.


The overlaying of a thin coating of noble metal on metallic components to improve conductivity, provide for easy soldering or prevent rusting or corrosion.


The part of the two mating halves of a connector that is free to move when not fastened to the other mating half. The plug is usually thought of as the male portion of the connector. The plug may have female contacts if it is the "free to move" member.


The arrangement of mating connectors such that the connectors can be mated in only one orientation.

Polarizing Pin, Key, or Keyway:

A device incorporated in a connector to accomplish polarization.

Polishing (Fiber Optic):

The act of smoothing ends of fibers to an "optically smooth" finish, generally using abrasives. Optically smooth surfaces allow maximum transmission of light between fibers at connections, and minimize coupling loss.


A thermoplastic with toughness, flexibility at low temperatures, resistance to chemicals and moisture, processability, and relatively low price.

Polytetrafluoroethylene (PTFE):

This is the most thermally stable and chemically resistant of all carbonaceous insulating compounds. It is unaffected by sunlight, moisture, and practically all chemicals. Temperature range is -90° to 250° C and electrical properties are very constant over the temperature range and a wide range of frequencies.


The sealing of a cable termination or other part with a liquid composition that hardens into an elastomer or solid plastic material.

Pre-Tinned Solder Cup:

Solder cups whose inner surfaces have been pre-coated a small amount of tin lead solder.

Press-fit Contact:

An electrical contact that can be pressed into a hole in an insulator, printed board (with or without plated-through holes), or a metal plate.

Printed Circuit:

This term is in common use with at least two meanings: 1) A generic term to describe a printed board produced by any of a number of techniques used to fabricate electrical interconnect systems. 2) A circuit obtained by printing and comprising printed components.


Abbreviation for polytetrafluoroethylene, commonly known as Teflon.