These are two bolts I turned on the lathe for our FRC robot in March 2023. It was an emergency job: the robot's elevator sheared two of the original bolts, so I made replacements by turning down regular socket head cap screws into shoulder bolts, with knurled heads and threaded ends.
They've since been pulled out in favor of alloy steel replacements. For the record, these same parts (same type, different instance) failed in subsequent years as well. I have come to hate them.