Understanding JAN/ MIL level Diodes and Transistors

Have you ever had trouble understanding the different levels of Military Diodes, and Transistors?

Have you ever tried to purchase a JAN level Diode or Transistor and found that the specific one you need is just not available or has a long lead time?  Hopefully after reading this you will have a better understanding of what the different levels mean and maybe you can find an acceptable alternate or upgrade to meet your production deadline.

JAN Prefix

First off adding a JAN prefix (or sometimes suffix) to a Transistor, or Diode is significant.  The JAN prefix stands for Joint Army Navy. Basically that means that the item is made to a Mil level (specifically MIL-S-19500).  So if you add a JAN to the 2N2222, you are buying you are purchasing a Military grade item.  But there is much more to it than that.

What if you need a JANTX, JANTXV, or a JANS?

First things first, adding anything after the original JAN does upgrade the part.  Adding a TX means that the part was not only made to MIL-S-19500 but it was also tested to that Mil spec.  Adding a V to the TX means that the part was verified during testing before the package was completed.  And adding a S to the JAN says that the part is space qualified or tested to Lot Tolerance Percent Defective (LTPD per MIL-STD-105).

Please see the following breakdown.

  • 2N2222 Commercial Part
  • JAN2N2222 Military Part made to MIL-S-19500
  • JANTX2N2222 Military Part made to MIL-S-19500 and tested to the spec after production
  • JANTXV2N2222 Military Part made to MIL-S-19500 with the die visually checked during production and tested to the spec after production
  • JANS2N2222 Military Part made to MIL-S-19500 with the die visually checked during production and tested to the spec after production. Then tested to LTPD following all other steps.

So then truly if you are looking for a part made to JAN level and you can only find a JANTXV item you might pay a bit more but you are truly getting a better part.

What if you find a part only marked JX or JTX?

Here are some of the common abbreviations and alternate was some manufacturers mark their parts.  Mostly if the part is too small to fit the entire part number.

  • JAN – J
  • JANTX – JX, or JTX
  • JANS – JS

What if you see an item marked MX?

Well, that is an interesting one.  In some cases, manufacturers who once held a QPL to make JAN parts found the it was not cost affective to keep up the QPL for that item.  In these cases, the manufacturer will still make the part and test it to MIL-S-19500, but because they don’t have the license to mark them JANTX, they will mark the part MX.

Can you use parts marked MX?

In our experience about 50% of our customers can us the MX items.  Most of the customers who can use these parts are using the parts for Navy builds.  The Navy has allowed suppliers to supply them with parts that are equivalents as long as the testing was completed to the MIL-S-19500 and there is proof in the form of paperwork to back up that the testing was done.


So there you have it. A brief overview of the different levels for ordering JAN Diodes and Transistors.  Hopefully this helps.  If you have any questions about any of this or would like to order any of these parts from Cornerstone Components, please just give us a call.  We have decades of experience handling these parts and can really help with all your needs.

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