I have a hitch mounted bike rack with a screw-in hitch-pin (the pin is half-threaded and screws into threads in the part of the bike rack that slides into the hitch receiver tube). It has a lock washer and flat washer on it too.
I mount and dismount the rack from the car's trailer hitch one or twice a week, it's about 2 years old so has had close to 200 cycles of screwing it on and unscrewing it from the rack.
It looks fine, no signs of wear, rust etc, and it seems to hold the rack securely.
Is there a limit to how many times a bolt/pin (and washers) like this can be re-used? Do I need to lubricate it? If the pin has a limited lifetime, do the threads in the bike rack also have a similar lifetime?
The pin looks like this:
And it screws in here:

