Baomain Aluminum Air Manifold Block, 5-Way 8-Port, 1/4" PT Threaded for Pneumatic Systems

As advertised. Good quality.

The threads are not right, too tight 1/4 pipe thread ....as in , 90% of what all home and contractor air tool fittings and hose ends are.So, right off whenever I read air fitting complaints I figure it's someone that doesn't have a clue that these numbers are the inner diameter...but not in this case. A quarter inch male air fitting will go in about 1 turn into this thing. So I found a good steel fitting and turned it in the one turn til it got tight...then i put in in the vise and turned it in all the way with a large crescent wrench...then chased back out. Upon inspecting it, the threads did not strip, they are just EXTREMELY TIGHT. My guess is that whoever set up the machine to make these used the wrong tolerance TAP . Right thread size, pitch but wrong tolerance tap. Taps come in different "tightness" tolerances ...has nothing to do with fine or coarse thread. They are selected based upon the tolerance required for the part. These tolerances are defined by the symbols class 1B, 2B, or 3B. Class 1B has the broadest tolerance and is generally applied to DIY (Do It Yourself) type nuts and bolts. Class 2B is the most common and is used for general fasteners and threaded parts. Class 3B is the tightest tolerance and used for close fit and high strength fastening applications, primarily in the automotive and aerospace industry. ---so, if the threads were wrong, I think my steel tap would have stripped out this manifold, but it didn't, it just wore down the threads a little. In short, look elsewhere for a air splitter/mainfold. You are NOT gona get fittings into this thing without a good vise, a 12" crescent wrench and brute force. As you can see in my pic, after brute forcing a steel fitting in and back out, the threads are all still there, so the thread is right, it's just too tight a tolerance. I tried this on a couple ports and they are all tight like this. Time wasted that I cant get back .