I had a set of these as a kid and had completely forgotten about them until I saw this set. These pencils have the simplest clutch possible, I think. The black nosepiece is held in the barrel by friction alone. There are no threads. The clutch jaws are on the inside end of the nosepiece. As the nosepiece is slid into the slightly tapered bore of the barrel, the jaws are pushed against the lead holding it surprisingly well.