I'm like crooketarrow, mine are all hafted on, I believe they are stronger than screw-in types or glue-on types. After thousands of shots I found that as the sinew starts to wear a little I smooth it back down with clear fingernail polish (lacquer) and they are good to go for way more shooting. I have never lost one in a target or a game animal, and given the choice I wont shoot anything but the hafted heads. Here's a pic to show how I do then, even with different head styles I still haft them
JMO
rich