[GreenKeys] Telephone Can Wrench

[Jerry Barnish]

Hello All:
 
This question has nothing to do with TTY. I work for a transit company
as a two way radio tech
and have been working with telephone comms for about 25 years.
 
Does anyone know why the wrench used for telephone enclosures and
lightning arrestors
is called a  can wrench?
 
The gang I work with never believed me until I showed them a package at
Graybar as a 
bona fide published source.
 
They are very argumentative and would like to know the reason, if any
for my own knowledge.
 
This reflector is great.
 
Jerry WB2CAK