Earls 982306ERL Blue 45 Degree Elbow -6 AN Male to 1/4 Inch NPT

This is a great fitting when used properly. However, I caused myself a big problem by trying it dry in the radiator. First, I picked it because I thought a hard steel fitting might damage the aluminum radiator inlet from my LS3 steam tube. Anyway, I tried the part dry in the radiator and tightened it up a medium amount with a wrench. I seemed to tighten up a lot at the last second. It had GALLED. This is like cold welding as the material slides and adheres together. When I tried to back the fitting out I could not with the wrench that had put it in. I tried penetrating oil and eventually forced it out with heavy vise grips. At least two threads from the fitting were left in the radiator fitting dry welded in place. The metal left in would not come out with a steel pick. I ordered a 1/4 NPT tap online and eventually was able to clean up the threads in the radiator. I worked very carefully a little at a time with oil. What a relief. So, always use a lubricant on aluminum thread like anti-seize. That my lesson!!!