i recently purchased a fuel line to go from my aem fuel rail to fuel filter. however the adapter which screws into the fuel filter snapped cause it was aluminum and i tightened it too much. i know its an 6an fitting but not sure to what npt size? ive purchased a 6an-1/4npt too big then i returened it for a 6an- 1/8 and was too small. i need to know what size the correct adapter is so i can order the correct one. Thanks!

 

12M x 1.25mm These are japanese cars, its metric not standard.

 

so what do you think i should tourque this adapter too?? its aluminum and snapped pretty easily and they do not make an steel adapter in that size

 

True its aluminum, but its not that easy to break. You had to either be going in at an angle or way over torqued it. Just let it sit correctly with the o ring and your set.

 

hehe yeh i made that mistake a long time ago also.

I normally go with hand tight, or till the threads are set... then no more than 1/4 turn