I also have 2 one stripped one not. I switched the end pieces and now they both tighten down, give it a try maybe it will work for you too. I like my my thick cap ball end too, but find the thins to be slightly better, the Single Rings are even better. I think the Single Ring has a better balance than the Ball End.This is my second thin cap single ring. My other one has stripped threads so I thought I would try and snag a second one. I used the new one and it shaves like the other one. That being a very close shave that requires a careful touch. The alum speaks loudly to me after I shave with these razors. But once my face settles down, the shave is as close as any I have had. I also like the look of them better than the ball end razors. But the ball end with a thick cap does give me a smoother shave. Still trying to decide which one I think shaves better. The single ring wins on looks alone though.