Nieto Safari Pommel Nut Help

[jimflynnjr]

I’ve had an M Nieto Safari with stacked leather handle since I sold knives back in the 90’s. I might have used this knife three time in the last 25 years. I pulled it out the other day and the pommel was loose. The thing I’m having trouble with is that the butt nut on this knife is not ‘slotted’— there’s no way to use a tool to tighten it. I can get it kind of tight, but not tight enough to use. How would one go about tightening this? Is it that the leather has shrunk or would they have used something like LockTite on the threaded end of the tang?

Thanks in advance