Easiest way with female threads is just to test fit a known male thread. I'd be surprised if mudguard eyes were bigger than M6, M5 is the most common size but M6 is sometimes seen. Screwing Ti into Ti has more potential for galling, but whatever you use you need to lubricate the threads with Copaslip or similar.
Easiest way with female threads is just to test fit a known male thread. I'd be surprised if mudguard eyes were bigger than M6, M5 is the most common size but M6 is sometimes seen. Screwing Ti into Ti has more potential for galling, but whatever you use you need to lubricate the threads with Copaslip or similar.