First, in case you didn’t know what a threaded insert was. Threaded inserts are small plastic or metal cylindrical shaped pieces with threads on the inside and and course threads on the outside that allow it to lock into an existing hole. Threaded inserts are great for adding strength to connections in wood or repairing stripped out threads. Many woodworkers use the threaded inserts for making shop jigs and fixture that have adjusting knobs.
Sometimes getting the insert to cut into the hole nice and straight can be a bit of a challenge. This easy to make little jig holds the threaded them straight while it is threaded into the wood saving you a little bit of frustration. You can see the full build over at LumberJocks