I’ve been working on getting a batch of chrome plating out to my plater, and one set of parts that were left were the door and trunk locks. The locks have to be disassembled so they can be chrome plated. I took the three locks to my local locksmith, and he managed to disassemble the door locks, but had trouble with the trunk lock. They finally gave up and stopped before damaging the lock.

The set screw that held the lock cylinder together was seized in the lock and no amount of penetrating oil or pressure would move the screw.

After soaking the lock in oil overnight, I tried some more. With the set screw already chewed up, I tried the next level of force by hammering the edges of the screw with a sharp point hoping to force the screw to turn with no luck.

The last resort was to put the lock in my Bridgeport and drill out the screw. I started with center drilling the set screw, then drilling down the rest out with a drill bit. I say this all the time, but I love my mill!

I managed to drill right down the center of the seized set screw and disassemble the lock. I also made a new set screw, cleaned up the threads of the lock cylinder, but will have to get a finer saw to cut the tiny screw driver slot in my new set screw. The lock surround can now join the rest of the parts for chrome plating!