You know, when the blade of a slipjoint stops halfway open.... and closed.
It's not that simple, most if not all slipjoints are pinned together.Just take the knife apart and grind off one corner of the tang and put the knife back together again.
I've rounded them a bit with a Dremel and a cut-off wheel to smooth the action a bit. I suppose you could continue in that manner and remove the resistence completely. I generally do a little damage to the liners in the process, though. You'd have to be very careful, and you need a dress stone to flatten the edge of the cutoff wheel, otherwise you won't get the very edges of the blade tang.
If the knife had a half stop and it was anywhere near flush in that position it will likely cause problems. If you can take the blade out and radius both corners without taking any metal off the very end of the tang it may work. If you do take anything off the end of the tang it will likely be loose anywhere near that position. Ken.
It's not that simple, most if not all slipjoints are pinned together.
I ain't exactly inexperienced, and I still appreciate the extra effort that goes into a well-executed half-stop.