your right,,,the first time i was putting grease in a fitting (the very first fitting ,i might add),the zerk fitting snapped of when i was removing the grease gun,,,,,after a time retrieving the broken off piece,i proceded to change out all of them with stronger ones,and also changed them to 45,and 90 degree angle one for easier access

 

im gonna change every nut i take out from now on, i bought a flexible pipe for my grease gun it makes it a lot easier to reach them now, some of them are a pain to get to