ORIGINAL: Hoytail Hunter
Becausewith slick tricks, tightening the BH onto the shaft also does the job of securing the blades onto the head. It's not like on a muzzy for example where the blades are fixed to the BH first then the BH screws onto the shaft. This is why you have to make sure they're tighter than hand tight.
Thought the same thing when I first got mine...still may be true, but I know I just tightened them with my fingers, shot for weeks into my broadhead target, then shot a doe, buried the arrow about 5" into the ground and the heads never loosened, nor did the blades.