I think one side is just threaded into the other through the blade with thread locker on it. It may have had some particulate in the female side that stopped it from tightening all the way. They probably just want to do it in house, just in case the thumb stud needs replacing for whatever reason...such as the female side being clogged or not being drilled out deep enough. I had an issue with one of the chopsticks in one of the customized sets I bought. I thought the carbon fiber tube had been cut too short. It turned out there was a tiny ball of the anodizing material in the bottom of the cap that wouldn't let it tighten completely against the tube. I sent it in, and they fixed it, returned it, and refunded my shipping costs. They just prefer to wait till they have things in hand to make the call on that sort of thing. Six knives, and three sets of chopsticks, only one issue, and excellent customer service on the one issue.