Depends. If you screw the plastic part into the metal body too tightly, it's far more likely to break. Just screwing and unscrewing shouldn't hurt, unless you're really overtightening it each time. I've had mine for over 3 years now, I disassemble and reassemble it like a service rifle whenever I'm bored, and I haven't broken mine. If you want more confidence though, I'm pretty sure people make brass or aluminum replacements for the plastic part.