It depends what you use them for. If you arange them so the force on the bolt is driving the spikes into the wood, they are very strong, and a handy way to anchor a bolt into wood in a removable way. Where they’re not so good is when the force isn’t directly along that line. Sideways force tends to loosen them and then they fall off, and force in the opposite direction obviously pushes them out.
It depends what you use them for. If you arange them so the force on the bolt is driving the spikes into the wood, they are very strong, and a handy way to anchor a bolt into wood in a removable way. Where they’re not so good is when the force isn’t directly along that line. Sideways force tends to loosen them and then they fall off, and force in the opposite direction obviously pushes them out.