Installing Heli-Coil style thread inserts. They cheaper, faster, and easier to install than Time-Serts. They do not require counterboring or thread locker. You don’t need threadlocker on this insert because it’s a spring and made of spring steel. The insert locks itself in place from the tension as it winds into the threads. Once you get about halfway in, the coil is under enough stress that it grabs tight and won’t back out, so your committed at that point. That’s what gives it a solid hold wit