1/2" ID fitting ID?
 

Hey if the hose is 1/2" ID what size should the ID or OD of the fittings be? OD around 1/2" and ID around 3/8"(of the fitting)??

If you have 1/2" ID hose then you buy 1/2" fittings. Most fittings don't give you a choice on inside diameter. Although if you check, a lot of nylon and plastic fittings have a greater actual inside diameter. They're all a bit different on the ID of the fitting. Look at them and compare when you buy. I have some that I got from Danger Den that are 1/2" fittings but I have some 3/8" nylons that I got locally that measure larger on the ID.

I always go one size up for the fittings to not constrict flow. So if you have 1/2" tubing try to find 5/8" fittings. For fittings the size is the OD so if you use 1/2" connectors you're dropping down to around 3/8" ID or so.

Also, dont forget, you can always ream out the fitting a little to get a litle extra ID.