Small solenoid rod length question

[nickseifert]

Hey,
I'm considering buying one of your small solenoids: http://www.adafruit.com/products/412. In the tutorial for the biometric lockbox which uses that solenoid there is some kind of extension connected to the end of it. See this picture: http://learn.adafruit.com/assets/3255.
I was hoping to find out: is the spring end of the armature threaded, or how is this extension connected? if it's threaded what is the tap size/pitch?

Thanks,
Nick

[adafruit_support_bill]

It is a 4-40 threaded PC-board standoff from the junk box. It is not essential for the project. I just mounted the solenoid a bit too far back and that piece happened to be the right size & thread.

[nickseifert]

OK, thanks. i will be needing an extension and wanted to make sure it was threaded.
Thanks!