Originally Posted by sakadachi

I think the primary reason it broke was from the heat. I use a Wera ratchet driver and can screw those setscrews rapidly. It creates A LOT of heat. The tool was probably not properly heat cycled at the factory. I will say that my Wera bits have not cracked like this..ever. But then I use Wera drivers for my real car hobby too, so durability is probably under much higher standards.