How to measure Medeco Cam lock

[slash007]

I need to replace a lock in my Portal and am trying to figure out what size I need. If I for example order a 2" extension lock like in this link:

https://www.kleen-ritecorp.com/p-45889-medeco-63w-750-m7-k-threaded-extension-lock-with-key-2.aspx

where is the 2" measured from? Is it the whole lock from where the key goes to the end of the stem, or just the threaded part?

Thanks.

 

[OurTown]

It's usually the length of the threaded part.

 

[MEP001]

It's measured from the flange that sits flat against the door to the point where the cam rests. It's what they call the "A" length.

 

[slash007]

Thanks!