TO-18

BC108 family transistors from various manufacturers in a TO-18 package.
Cross section of 2N2222 transistor in metal TO-18 package, showing connection wires between external pins and die.
Size comparison between (left to right) TO-39, TO-18, and TO-92 packages.

In electronics, TO-18 is a designation for a style of transistor metal case. The case is more expensive than the similarly sized plastic TO-92 package. The name is from JEDEC, signifying Transistor Outline Package, Case Style 18.[1]

  1. ^ Cite error: The named reference TO-18_Spec was invoked but never defined (see the help page).