https://www.fastenright.com/stainless-steel-hexagon-bolts-din-931. Rotation of a hexagon bolt (Din 931).
This video shows how to replace a door knob; with or without screws, and both locking and non locking types. Repair or replace your door knob with the help of this video. Check out the bloopers at the end. Subscribe if you like this one because I have many more.
Video on how to replace a lock set on an exterior door can be found on my channel here https://youtu.be/gKARRUWu5y8