Where to buy barbs? Hardware store?

Hello, I am wondering if it is possible to buy some 1/2" barbs for my heatercore at a local hardware store? Do you think they would carry them? Or are they a water cooling specific item that must be ordered online or at computer shops?
If the hardware store would have them, what am I asking for? 1/2" OD barbs made of copper/brass/what??

Barbs

Most of hardware stores will either have something close or be able to send you to somewhere that does. We have 8 or 9 stores in my area all with slightly different sets of stock. It'd be a good idea to bring in the core/block so you can find one that matches. I've wasted a lot of time running back and forth for work (research lab) when I needed something strange.
As far as what metal, that's a decision you have to make based on what your rad and blocks are made of. Generally, you want everything to be of the same metal to prevent galvanic corrosion. I'm sure there's a lot of posts on that if you want to search (what metal to use, etc). Good luck.
mgweir

Go to mcmaster.com, they've got more barbs than you can shake a stick at
I'd recommend the push-on hose barbs on page 224, they make for a very nice leak free connection.

Otherwise, go to the plumbing department in Home Depot or Lowes. Most of the barbs will be brass or plastic.

You also need to know what thread size your HC needs. I'm guessing that it's 1/4" NPT

USPlastics.com is better for small orders as some mcmaster items must be bought in packs. They also seem to be cheaper in many areas.

generally homedepot has them

plastic is best, so you don't crack what youre screwing into