If you want to make your pi more industrial and connect it to some din rail and want a relatively cheap solution I found a couple parts that can your Raspberry Pi for under $15.
Comes with a 24v power input and doesn't take too long to make...
Parts:
BUD Industrial Plastic Din Rail Box
.
7-24v to 5v 3A DC-DC Converter
:
And some time cutting tools... I was able to use a Dremel. (and even with that I made some crooked cuts)
Cut out slot for the 24v dc converter
Cut out usb & lan slots