This drill setting tool is ridiculously underengineered. The first time it was used it broke at a weak point. I had to weld a reinforcement plate to the tool near the knee before it could be used for its intended purpose. After reinforcement, the tool could position the drill bit without deforming the tool. If welding wasn't practical for me, the tool would be useless. I used this tool with a 6" flexible drill bit and a 1/4" shank. "Shenk was used.)