TO-206 Component Package

Article by:
Date Published:
Last Modified:


The TO-206 (Transistor Outline Package, Case Style 206) component package is a family of large through-hole metal can packages used for things such as transistors. There are variants with anywhere from 2 to 8 leads1.


  • H03C: What National Semiconductor calls the TO-206AA2.
  • TO-18


  • TO-206AA: The popular 3-lead variant. Also called TO-18-3.
  • TO-206AB: 3-lead with 1.90mm cap height. Also called TO-46.1
  • TO-206AC: 3-lead with 3.30mm cap height. Also called TO-52.1
  • TO-206AF: 4-lead. Also called TO-72.
  • TO-71: 8-lead TO-18.

Common Uses

  • Diodes (TO-18-2)
  • Transistors (TO-18-3)

Similar To:

TO-206AA (TO-18-3)

The TO-206AA is the most common 3-lead version in the TO-206 family. It is also known by it’s older name as the TO-18-3 – or just ambiguously as the TO-18. National Semiconductor called this package H03C2. Transistors such as the 2N2222A BJT are available in this package.

A photo of the TO-206AA (TO-18-3) from DigiKey[^digikey-2n2222a].

A photo of the TO-206AA (TO-18-3) from DigiKey3.

The dimensions of the TO-206AA are shown below:

Dimensions for the TO-206AA (TO-18) component package from National Semiconductor (now Texas Instruments)[^ti-metal-can-packages].

Dimensions for the TO-206AA (TO-18) component package from National Semiconductor (now Texas Instruments)2.


  1. Wikipedia (2021, Nov 19). TO-18. Retrieved 2023-06-12, from↩︎ ↩︎ ↩︎

  2. National Semiconductor (now Texas Instruments) (1999, Aug). SNOA033 - Metal,Can,Packages - Metal Can Packages (TO-3/5/8/18/39/46/52/72). Retrieved 2023-06-12, from↩︎ ↩︎ ↩︎

  3. DigiKey. Central Semiconductor Corp 2N2222A PBFREE. Retrieved 2023-06-12, from↩︎


Geoffrey Hunter

Dude making stuff.

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License .

Related Content


comments powered by Disqus