For EDiscovery legal copies..
ISO files are CD or DVD image files...
You may consider what I've used in the past - before virtual machines became the right tool - something like Norton's "Ghost" application. This type of app makes an image file of your HDD. It is intended to be used to "flash" an operating system back onto the main disk so that a clean system can be used for testing -- or traditionally, it's a HDD backup application which restores the HDD contents via it's image file.
You may want to consider that or otherwise grabbing content off the HDD into a file and copying that 5 more times.
Do any of these ideas meet your needs?
Thanks John. I'm hoping there might be a device (besides a hub) which allow me to simultaneously duplicate one USB External to six new USB Externals .5 Tb to 1 Tb in size. I proposed using internal SATA drives and using the Aleratec IDE SATA Hard Disk Duplicator then inserting them into an external enclosure converting it to an external drive.