interesting subject..........I just hack sawed about 3/16" off the male end of my stacker because there wasn't enough exposure of materials after tapping. I used a 8" long wooden dowel, wrapped it with tape to make a snug fit with the inside diameter of the male end and then mounted it in a vise to cut. I then filed the rough edges down holding it with the same dowel arrangement. be sure there are no rough edges remaining