Hydro Flow Barbed Tee 1/2 Inch, Bag of 10

Product's actual outer diameter: .550" (14mm). Since this goes inside the dripline, you want to compare that to the inner diameter (ID) of your dripline.From all the angry reviews, it's clear a lot of other customers are like me before I ordered 500' of "1/2 inch dripline" from Amazon a few months ago!As I soon discovered, what people call "half inch dripline" can range from about .620" to .710" OD (outer diameter) and something like .520" to .615" (inner diameter). (Note none of these are "half inch".) It turned out what I got was .630" OD and .540" ID, which is a lot smaller than the .700" that seems to be most common. At a pro shop I found, they talk about 16mm, 17mm, and 18mm. Mine is the "16mm" but they don't carry much for that size.So, now that we're all enlightened, you shouldn't buy anything off Amazon for your drip system without knowing what the true sizes are, and that means you can't just buy a product like this that says "half inch" and doesn't even bother to list the actual diameter. But I have taken calipers and measured the outside edge of the barbs are .550". So for me, with my .540" ID Rain Bird dripline, this fits slightly snug but you can easily pull them out again. They seem to be watertight for me but I'm regulating my pressure to around 30psi (which is a good idea). They would probably get blown off at high enough pressure, and I wouldn't be surprised if they fail in time since they're not very tight. So I can't really recommend these.

Have purchased Hydro Flow Premium Barbed Tees and Elbows to connect 1/2" (RB) Poly Drip Line. These 'Premium' Fittings are terrific. They have plenty 'Barb' plus plenty of 'Friction Room' on the fittings. My particular situation is somewhat unique. I'm running Drip Lines along a 500+ ft slope to supply Drip Fields under mature trees along a treeline. The intent is for a relatively permanent installation; hence I am also using PEX Ring Clamps at each connection, just to ensure extreme wx elements (and pressure) doesn't cause a connection to 'pop loose'. However upon testing several of these initial Fields I've built, I've discovered that Hydro Flow's 'Premium' Fittings fit so well that I didn't need to crimp a PEX Ring around them to test my Fields. This is somewhat surprising because many other types/brands I tried "Popped-Off" immediately as I applied water; and I'm only supplying a regulated 30 psi. Very happy with Hydo Flow 'Premium' Fittings.

Runs smaller than other 1/2 inch fittings. if you are using these for a waterfarm hydroponics system they will leak at the grommet since they appear to be measuring from the outside diameter of the barb. the correct ones are item number four one six one.

Yes, I am an idiot....I ordered 1/2" barbed T fittings, and thought these would fit my trove of 1/2" poly pipe and dripline..... UH..... mismatch in measuring systems. THESE ARE 1/2" at their very widest. But nowhere near a proper match for what we call 1/2 " poly pipe. AMAZON SHOULD REQUIRE better description.

I ordered 1/2 inch. The bag said 1/2 inch, yet it was too small for a 1/2 inch pipe. The fitting was around 1/4 not 1/2. Wasted my money. Wasted my time. Set me back close to a month on my project because I had to wait for these to come then I had to reorder a different company to get ones that fit.Wasted my time and I am very angry.

On the one hand. I want to give these a good review, on the other hand, they did NOT work with my Rain Bird T63-500S Drip Irrigation 1/2" (.630" OD) Blank Distribution Tubing. Apparently 1/2 inch does not mean 1/2 inch. These fittings required hose clamps to work with this tubing, and even then they leaked. From more research, it looks like the tubing is at fault, so leaving this review so others know...

It does its basic job of connecting 1/2 hoses, but these things are so short... these are often put through a rubber gasket/grommet. By time it goes through the grommet, there’s barely enough to connect a hose to. It’s ridiculous. If they would make these a half inch longer, you could actually connect something on the other side. I won’t be purchasing these again.

DOES NOT fit RainBird 1/2" supply line which is what most buy and as others stated but I ordered it anyway and its not even close. I was not about to start using clamps on every connection so I bought the RainBird connectors and they are awesome! Super super tight as these should have been.