Weldon holder
Weldon holders are designed for tools with a local flattening on the shank. The tool is fixed by tightening the screw in the holder, which presses the flat on the tool, preventing it from turning.
Weldon holders are most often used to clamp milling cutters. In rough machining, where there are high milling forces, the screw pressure protects the tool from tearing it out of the holder.
Weldon holder
End mill weldon shank
