Some Compression Fittings Strip Acetal Threads

I'd just like to warn people about compression fittings that have sharp grooves in them, such as these:



They were actually the first set of compression fittings I bought, because they were cheap and I didn't mind the low-profile look of them. I bought about 15 of them in total, and they're all sharp. Sharp enough to slice through my pasty-white skin when I tightened them or removed the tubing by hand. Apparently it's virtually impossible to screw them into acetal waterblocks / reservoirs without stripping the threads, because no matter how careful you are, they *will* dig into the threads and refuse to screw smoothly all the way in without taking chunks out of the acetal. In addition, there is also a sharp groove on the barb end which may also slit your tubing. They go into brass threads on radiators no problem, though.

I've used Monsoon fittings and have no problems with them.

Infact they were the easiest fittings i've ever used. The EK compression fittings I used years ago were much harder to get a proper seal and my fingers were destroyed.

The Monsoons don't have the groove on the screw end at least, but I don't know how sharp the groove on the barb is or how easily tubing slips over it without being cut by it. Primochill Advanced LRT tubing is a tight fit, I know that much.