"You pay peanuts you get Monkeys".
Quality is very bad. The match between the thread of this blindnut and an actual M4 is very poor. When screwed to the screw, it can still move sideways which means the thread were badly formed or its geometry is wrong.
In my process of tightening the blindnut and screw on a plywoood panel, the thread of the blindnut actually gave way. As a result I had a failed blindnut partly still attached to the screw and I'm unable to unscrew it as the thread is damaged and its in an enclosure I cannot reach in.
If you want really fair quality blindnut, I suggest you purchase it from your local hardware store. These are just hopeless!
Thanks HK for this ****!
The blindnut must be tightened on the plywood like you should do it with a nail and a hammer ! You cannot do it by screwing. Of course you destroyed the thread with your process. Better change your process. The blindnuts I receive are not specially precise but enough for general modelist use as I do ...