Coil insert installed to full depth. Make sure to install at least one or two threads below the deck of the surface you’re installing into. Otherwise the end is prone to popping out or making it hard to start screws into the hole. I’d bet not installing deep enough is the most common cause of failure for this type of thread repair. Notice the tang at the bottom of the hole. It is partially cut already when new. A sharp rap with a punch and hammer breaks it off easily without disturbing the coil. This is the other main area people mess up. You must remove the tang. Otherwise it will damage the coil when you install the screw later and mess up your repair.