I highly doubt it's a shipwreck part. Or to the extent it could have come off a boat of some sort, perhaps regular fishing vessel, pleasure craft of fairly modern vintage, etc... But more likely: Just fumble fingers regular beach stuff.
We have a beach near me, where the dunes were used for municipal dumping back at the late 1800s/early 1900s. And now, 100 + yrs. later, the erosion has nibbled back this far into the dunes. And stuff like that is ALWAYS turning up on the beach . Endless little hardware and house ware nicknacks, gear stuff, mechanical doohickys, etc....