It's a threaded tang, with a Clevis and coupler in the assembly..... that way there is allowance for slight side to side and top to bottom movement to ensure that the front of the handle material lays square on the guard, and that the buttcap is true with back of the handle material. It's the same assembly that I used to use with "Take Downs".....but I stopped making knives that could be disassembled/reassembled after having to repair a bunch of them sold to individuals who tore all kinds of things up on them....mostly out of carelessness, then wanted me to repair them for free. Now when somebody requests a "Take Down", I tell them..... "Sure! I can do that, but it will glued up completely before it leaves my shop!"
