TO-3 at Motorola around 1955. The lead spacing was originally intended to allow plugging the device into a then-common tube socket. The metal package can be attached to a heat sink, making it suitable for devices dissipating several watts of heat. Thermal compound is used to improve heat transfer between the device case and the heat sink. Since the device case is one of the electrical connections, an insulator may be required to electrically isolate the component from the heatsink. Insulating washers may be made of mica or other materials with good thermal conductivity. The case is used with high-power and
Bench jeweler same for jewelry casting. The cast pieces will likely need a variety of work done to them, including filing to remove the skin left from casting and prepare for polishing, straightening parts, rounding and sizing rings, and assembling many various parts together using solder. Although the method used is called soldering, it is actually a form of brazing, using "solders" of the metal being worked, i.e. gold solders for gold pieces, silver solder for silver pieces, etc. All of this is the work of bench jewelers, who at this level are sometimes known as production workers in some arenas. In